Information Security: Effective Patch Management is Critical to  
Mitigating Software Vulnerabilities (10-SEP-03, GAO-03-1138T).	 
Attacks on computer systems--in government and the private	 
sector--are increasing at an alarming rate, placing both federal 
and private-sector operations and assets at considerable risk. By
exploiting software vulnerabilities, hackers can cause		 
significant damage. While patches, or software fixes, for these  
vulnerabilities are often well publicized and available, they are
frequently not quickly or correctly applied. The federal	 
government recently awarded a contract for a government-wide	 
patch notification service designed to provide agencies with	 
information to support effective patching. Forty-one agencies now
subscribe to this service. At the request of the Chairman of the 
Subcommittee on Technology, Information Policy, Intergovernmental
Relations, and the Census, GAO reviewed (1) two recent software  
vulnerabilities and related responses; (2) effective patch	 
management practices, related federal efforts, and other	 
available tools; and (3) additional steps that can be taken to	 
better protect sensitive information systems from software	 
-------------------------Indexing Terms------------------------- 
REPORTNUM:   GAO-03-1138T					        
    ACCNO:   A08425						        
  TITLE:     Information Security: Effective Patch Management is      
Critical to Mitigating Software Vulnerabilities 		 
     DATE:   09/10/2003 
  SUBJECT:   Computer crimes					 
	     Computer security					 
	     Computer software					 
	     Crime prevention					 
	     Information systems				 
	     Strategic planning 				 

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Testimony Before the Subcommittee on Technology Information Policy,
Intergovernmental Relations, and the Census, House Committee on Government

United States General Accounting Office

GAO For Release on Delivery Expected at 10: 00 a. m. EDT Wednesday,

Effective Patch Management is Critical to Mitigating Software

Statement of Robert F. Dacey Director, Information Security Issues

GAO- 03- 1138T

The increase in reported information systems vulnerabilities has been
staggering, especially in the past 3 years (see chart). Automated attacks
are successfully exploiting such software vulnerabilities, as increasingly
sophisticated hacking tools become more readily available and easier to
use. The response to two recent critical vulnerabilities in Microsoft
Corporation and Cisco Systems, Inc., products illustrates the
collaborative efforts between federal entities and the information
security community to combat potential attacks.

Patch management is one means of dealing with these increasing
vulnerabilities to cybersecurity. Critical elements to the patch
management process include management support, standardized policies,
dedicated resources, risk assessment, and testing. In addition to working
with software vendors and security research groups to develop patches or
temporary solutions, the federal government has taken a number of other
steps to address software vulnerabilities. For example, offered without
charge to federal agencies, the federal patch notification service
provides subscribers with information on trusted, authenticated patches
available for their technologies. At present, the government is
considering broadening the scope of these services and capabilities, along
with the number of users. Other specific tools also exist that can assist
in performing patch management. In addition to implementing effective
patch management practices,

several additional steps can be taken when addressing software
vulnerabilities. Such steps include stronger software engineering
practices and continuing research and development into new approaches

computer security. Security Vulnerabilities, 1995* First Half of 2003
(11,155 in the aggregate) Attacks on computer systems* in government and
the private sector* are increasing at an alarming rate, placing both

and private- sector operations and assets at considerable risk. By
exploiting software vulnerabilities,

hackers can cause significant damage. While patches, or software fixes,
for these vulnerabilities are often well publicized and available, they
are frequently not quickly or correctly applied. The federal government
recently awarded a contract for a

governmentwide patch notification service designed to provide agencies
with information to support effective patching. Fortyone agencies now
subscribe to this service.

At the request of the Chairman of the Subcommittee on Technology,
Information Policy, Intergovernmental Relations, and the Census, GAO
reviewed (1) two recent software vulnerabilities and related responses;
(2) effective patch management practices, related federal efforts, and
other available tools; and (3) additional steps that can be taken to
better protect sensitive information

systems from software vulnerabilities.

www. gao. gov/ cgi- bin/ getrpt* GAO- 03- 1138T. To view the full product,
including the scope and methodology, click on the link above. For more
information, contact Robert F. Dacey at (202) 512- 3317 or [email protected] gao.
gov. Highlights of GAO- 03- 1138T, testimony

before the Subcommittee on Technology, Information Policy,
Intergovernmental Relations, and the Census, House Committee on Government


Effective Patch Management is Critical to Mitigating Software

Page 1 GAO- 03- 1138T Mr. Chairman and Members of the Subcommittee: I am
pleased to be here today to participate in the Subcommittee*s hearing

on recent cyber incidents and the role of software patch management 1 in
mitigating the risks that these types of events will recur. Current
incidents inundating the Internet, coupled with the increasing number and
sophistication of attacks, place both federal and private- sector
operations and assets at considerable risk. Several of these incidents
exploited software vulnerabilities for which patches were already publicly
available. In my testimony today I will discuss (1) two recent software

and related responses; (2) effective patch management practices, related
federal efforts, and other available tools; and (3) additional steps that
can be taken to better protect sensitive information systems from software

vulnerabilities. In preparing for this testimony, we analyzed professional
information technology security literature, including research studies and
reports about cybersecurity- related vulnerabilities. We also interviewed
privatesector and federal officials about their patch management
experiences. And we analyzed relevant documents and interviewed officials
of the Patch Authentication and Dissemination Capability (PADC) service
and supporting contractors to determine the service*s current capabilities
and usage. Finally, we reviewed actions taken by PADC and agency officials
in response to recent cybersecurity vulnerabilities. Our work was

in accordance with generally accepted government auditing standards, from
June to September 2003.

Since 1995, over 11,000 security vulnerabilities in software products have
been reported. Along with these increasing vulnerabilities, the
sophistication of attack technology has steadily advanced. Attacks such as
viruses and worms 2 that once took weeks or months to propagate over the
Internet now take only hours, or even minutes. In just the past 3 months,

1 A patch is a piece of software code that is inserted into a program to
temporarily fix a defect. Patches are developed and released by software
vendors when vulnerabilities are discovered. Patch management is the
process of effectively applying available patches.

2 A virus is a program that *infects* computer files, usually executable
programs, by inserting a copy of itself into the file. In contrast, a worm
is an independent computer program that reproduces by copying itself from
one system to another across a network. Unlike computer viruses, worms do
not require human involvement to propagate. Results in Brief

Page 2 GAO- 03- 1138T two critical and widespread vulnerabilities were
identified in products from Microsoft Corporation and Cisco Systems, Inc.
Federal agencies

were affected by the Blaster and Welchia worms, which exploited the
Microsoft vulnerability. The response to these recent events illustrates
how federal entities are communicating and coordinating with software
vendors and security research groups to combat such attacks. Effective
patch management, one means of dealing with these increasing

security threats, includes several critical elements, such as top
management support, standardized policies, dedicated resources, risk
assessment, and testing. In the federal arena, the Department of Homeland
Security now provides agencies with information on trusted, authenticated
patches for their specific technologies without charge. This service,
known as PADC, currently has 41 agency subscribers. Other tools and
resources also exist that can assist in performing patch management

Patch management is but one* albeit important and essential* component in
the protection of systems from security vulnerabilities. However, in the
longer term, the nation*s ability to withstand attacks may ultimately come
from more rigorous software engineering practices and better tools and
technologies. My statement today will highlight steps we can take now and
in the future to help reduce our vulnerability to cyber intrusion.

Flaws in software code that could cause a program to malfunction generally
result from programming errors that occur during software development. The
increasing complexity and size of software programs contribute to the
growth in software flaws. For example, Microsoft

Windows 2000 reportedly contains about 35 million lines of code, compared
with about 15 million lines for Windows 95. As reported by the National
Institute of Standards and Technology (NIST), based on various studies of
code inspections, most estimates suggest that there are as many

as 20 flaws per thousand lines of software code. While most flaws do not
create security vulnerabilities, 3 the potential for these errors reflects

3 A vulnerability is the existence of a flaw or weakness in hardware or
software that can be exploited resulting in a violation of an implicit or
explicit security policy. Background: Vulnerabilities and


Page 3 GAO- 03- 1138T difficulty and complexity involved in delivering
trustworthy code. 4 By exploiting software vulnerabilities, hackers and
others who spread

malicious code can cause significant damage, ranging from Web site
defacement to taking control of entire systems, and thereby being able to
read, modify, or delete sensitive information, destroy systems, disrupt
operations, or launch attacks against other organizations* systems.

Between 1995 and the first half of 2003, the CERT . Coordination Center 5
(CERT/ CC) reported 11,155 security vulnerabilities that resulted from
software flaws. Figure 1 illustrates the dramatic growth in security
vulnerabilities over these years.

Figure 1: Security Vulnerabilities, 1995* first half of 2003

The growing number of known vulnerabilities increases the number of
potential attacks created by the hacker community. As vulnerabilities are
discovered, attackers may attempt to exploit them. Attacks can be launched
against specific targets or widely distributed through viruses and worms.

4 National Institute for Standards and Technology, Procedures for Handling
Security Patches: Recommendations of the National Institute of Standards
and Technology, NIST Special Publication 800- 40 (Gaithersburg, MD: August
2002). 5 The CERT/ CC is a center of Internet security expertise at the
Software Engineering Institute, a federally funded research and
development center operated by Carnegie- Mellon University.

Page 4 GAO- 03- 1138T Worms and viruses are commonly used to launch
denial- of- service attacks, which generally flood targeted networks and
systems with so much transmission of data that regular traffic is either
slowed or completely

interrupted. Such attacks have been utilized ever since the groundbreaking
Morris worm, which brought 10 percent of the systems connected to Internet
systems to a halt in November 1988. In 2001, the Code Red worm used a
denial- of- service attack to affect millions of computer users by

shutting down Web sites, slowing Internet service, and disrupting business
and government operations. 6 This type of attack continues to be used by
recent worms, including Blaster, which I will discuss further later in my

The sophistication and effectiveness of cyber attack have steadily
advanced. Because automated tools now exist, CERT/ CC has noted, attacks
that once took weeks or months to propagate over the Internet now take
just hours, or even minutes. Code Red achieved an infection rate of over
20, 000 systems within 10 minutes, foreshadowing more damaging and
devastating attacks. Indeed, earlier this year, the Slammer worm,

which successfully attacked at least 75,000 systems, became the fastest
computer worm in history, infecting more than 90 percent of vulnerable
systems within 10 minutes.

Frequently, skilled hackers develop exploitation tools and post them on
Internet hacking sites. These tools are then readily available for others
to download, allowing even inexperienced programmers to create a computer
virus or to literally point and click to launch an attack. According to a
NIST publication, 30 to 40 new attack tools are posted to the Internet
every month. 7 The threat to systems connected to the Internet is
illustrated by the

increasing number of computer security incidents reported to CERT/ CC.
This number rose from just under 10,000 in 1999 to over 52, 000 in 2001,
to about 82,000 in 2002, and to over 76,000 for the first and second
quarters of

2003. And these are only the incidents that are reported. According to the
Director of CERT/ CC, as much as 80 percent of actual incidents go

6 U. S. General Accounting Office, Information Security: Code Red, Code
Red II, and SirCam Attacks Highlight Need for Proactive Measures, GAO- 01-
1073T (Washington D. C.: August 29, 2001).

7 U. S. General Accounting Office, Information Security: Weaknesses Place
Commerce Data and Operations at Serious Risk, GAO- 01- 751 (Washington D.
C.: August 13, 2001).

Page 5 GAO- 03- 1138T unreported, in most cases because the organization
was either unable to recognize that its systems had been penetrated
(because there were no

indications of penetration or attack) or because it was reluctant to
report an incident. Figure 2 illustrates the number of incidents reported
to CERT/ CC from 1995 through the second quarter of 2003.

Figure 2: Information Security Incidents, 1995* first half of 2003

According to CERT/ CC, about 95 percent of all network intrusions could be
avoided by keeping systems up to date with appropriate patches; however,
such patches are often not quickly or correctly applied. Maintaining
current patches is becoming more difficult, as the length of time between
the awareness of a vulnerability and the introduction of an exploit is
shrinking. For example, the Blaster worm was released almost
simultaneously with the announcement of the vulnerability it exploited.

Successful attacks on unpatched software vulnerabilities have caused
billions of dollars in damage. Following are examples of significant
damage caused by worms that could have been prevented had available
patches been effectively installed:

 In September 2001 the Nimda worm appeared, reportedly infecting hundreds
of thousands of computers around the world, using some of the most
significant attack methods of Code Red II and 1999*s Melissa virus that
allowed it to spread widely in a short amount of time. A patch had been
made publicly available the previous month.

Page 6 GAO- 03- 1138T  On January 25, 2003, Slammer triggered a global
Internet slowdown and caused considerable harm through network outages and
other unforeseen

consequences. As we discussed in our April testimony, the worm reportedly
shut down a 911 emergency call center, canceled airline flights, and
caused automated teller machine (ATM) failures. 8 According to media
reports, First USA Inc., an Internet service provider, experienced network

performance problems after an attack by the Slammer worm, due to a failure
to patch three of its systems. Additionally, the Nuclear Regulatory
Commission reported that Slammer also infected a nuclear power plant*s
network, resulting in the inability of the computers to communicate with
each other, disrupting two important systems at the facility. In July
2002, Microsoft had released a patch for its software vulnerability that
was exploited by Slammer. Nevertheless, according to media reports, some
of Microsoft*s own systems were infected by Slammer.

In addition to understanding the threat posed by security vulnerabilities,
it is useful to understand the process of vulnerability identification and
response. In general, when security vulnerabilities are discovered, a
process is initiated to effectively address the situation through
appropriate reporting and response. Typically, this process begins when

vulnerabilities are discovered by software vendors, security research
groups, users, or other interested parties, including the hacker
community. When a software vendor is made aware of a vulnerability in its
product, the vendor typically first validates that the vulnerability
indeed exists. If the vulnerability is deemed critical, the vendor may
convene a group of experts, including major clients and key incident-
response groups such the Federal Computer Incident Response Center
(FedCIRC) and CERT/ CC, to discuss and plan remediation and response

After a vulnerability is validated, the software vendor develops and tests
a patch and/ or workaround. A workaround may entail blocking access to or
disabling vulnerable programs.

The incident response groups and the vendor typically prepare a detailed
public advisory to be released at a set time. The advisory often contains
a description of the vulnerability, including its level of criticality;
systems that are affected; potential impact if exploited; recommendations
for workarounds, and Web site links where a patch (if publicly available)

8 U. S. General Accounting Office, Information Security: Progress Made,
But Challenges Remain to Protect Federal Systems and the Nation*s Critical

GAO- 03- 564T (Washington, D. C.: April 8, 2003).

Page 7 GAO- 03- 1138T be downloaded. Incident- response groups as well as
software vendors may continue to issue updates as new information about
the vulnerability is

discovered. When a worm or virus is reported that exploits a
vulnerability, virus detection software vendors also participate in the
process. Such vendors develop and make available to their subscribers
downloadable *signature files* that are used, in conjunction with their
software, to identify and stop the virus or worm from infecting systems
protected by their software. The Organization for Internet Safety (OIS),
which consists

of leading security researchers and vendors, recently issued a voluntary
framework for vulnerability reporting and response. 9 Recently, two
critical vulnerabilities were discovered in widely used

commercial software products. The federal government and the privatesector
security community took steps, described below in chronological order, to
collaboratively respond to the threat of potential attacks against

these vulnerabilities. Last Stage of Delirium Research Group discovered a
security vulnerability in Microsoft*s Windows Distributed Component Object
Model (DCOM) 10 Remote Procedure Call (RPC) 11 interface. This
vulnerability would allow

an attacker to gain complete control over a remote computer.  On June 28,
2003, the group notified Microsoft about the RPC

vulnerability. Within hours of being notified, Microsoft verified the

 On July 16, Microsoft issued a security bulletin publicly announcing the
critical vulnerability and providing workaround instructions and a patch.
 The following day, CERT/ CC issued its first advisory.

9 Organization for Internet Safety, Guidelines for Security Vulnerability
Reporting and Response, Version 1.0 (July 2003). 10 Distributed Component
Object Model (DCOM) allows direct communication over the network between
software components. 11 Remote Procedure Call (RPC) is a protocol of the
Windows operating system that allows a program from one computer to
request a service from a program on another computer in a network, thereby
facilitating interoperability. Collaborative Response to Two

Recent Software Vulnerabilities

Microsoft Remote Procedure Call Vulnerability Exploited by Hacker

Page 8 GAO- 03- 1138T  Nine days after Microsoft*s announcement, on July
25, Xfocus, an organization that researches and demonstrates security

released code that could be used to exploit the vulnerability.  On July
31, CERT/ CC issued a second advisory reporting that multiple

exploits had been publicly released, and encouraged all users to apply the

 On August 11, 2003, the Blaster worm (also known as Lovsan) was launched
to exploit this vulnerability. When the worm is successfully executed, it
can cause the operating system to crash. Experts consider Blaster, which
affected a range of systems, to be one of the worst exploits of 2003.
Although the security community had received advisories from CERT/ CC and
other organizations to patch this critical vulnerability,

Blaster reportedly infected more than 120,000 unpatched computers in the
first 36 hours. By the following day, reports began to state that many
users were experiencing slowness and disruptions to their Internet
service, such as the need to frequently reboot. The Maryland Motor Vehicle
Administration was forced to shut down, and systems in both national and
international arenas have also been affected. The worm was programmed to
launch a denial- of- service attack on Microsoft*s Windows Update Web site
www. windowsupdate. com (where users can download security

patches) on August 16. Microsoft preempted the worm*s attack by disabling
the Windows Update Web site.

 On August 14, two variants to the original Blaster worm were released.
Federal agencies reported problems associated with these worms to FedCIRC.
 On August 18, Welchia, a worm that also exploits this vulnerability, was

reported. Among other things, it attempts to apply the patch for the RPC
vulnerability to vulnerable systems, but reportedly creates such high
volumes of network traffic that it effectively denies services in infected
networks. Media reports indicate that Welchia affected several federal

agencies, including components of the Departments of Defense and Veterans

The federal government*s response to this vulnerability included
coordination with the private sector to mitigate the effects of the worm.

 On July 17, FedCIRC issued an advisory to encourage federal agencies to
patch the vulnerability, followed by several advisories from the
Department of Homeland Security (DHS).

Page 9 GAO- 03- 1138T  The following week, on July 24, DHS issued its
first advisory to heighten public awareness of the potential impact of an
exploit of this vulnerability. 12  On July 28, on behalf of the Office of
Management and Budget (OMB),

FedCIRC requested that federal agencies report on the status of their
actions to patch the vulnerability.

 From August 12 to August 18, DHS*s National Cyber Security Division
hosted several teleconferences with federal agencies, CERT/ CC, and

Figure 3 is a timeline of selected responses to the Blaster Internet worm.
12 Department of Homeland Security, Potential For Significant Impact On
Internet Operations Due To Vulnerability In Microsoft Operating Systems
(Washington, D. C.: July 24, 2003).

Page 10 GAO- 03- 1138T Figure 3: Event Timeline for the Blaster Internet

Based on an analysis of the agencies reported actions, as requested on
July 28, FedCIRC indicated that many respondents had completed patch
installation on all systems at the time of their report and that only a
minimal number of infections by the Blaster worm were reported.

Cisco Systems, Inc., which controls approximately 82 percent of the
worldwide share of the Internet router 13 market, discovered a critical
vulnerability in its Internet operating system (IOS) software. This
vulnerability could allow an intruder to effectively shut down unpatched
routers, blocking network traffic. Cisco had informed the federal

government of the vulnerability prior to public disclosure, and worked
with different security organizations and government organizations to
encourage prompt patching.

 On July 16, 2003, Cisco issued a security bulletin to publicly announce
the critical vulnerability in its IOS software, and provide workaround
instructions and a patch. Cisco had planned to officially notify the
public of the vulnerability on July 17, but early media disclosure led
them to announce the vulnerability a day earlier. In addition, FedCIRC

13 Routers are hardware devices or software programs that forward Internet
and network traffic between networks and are critical to their operation.
Cisco IOS Vulnerability

Exploits Attempted

Page 11 GAO- 03- 1138T advisories to federal agencies and DHS advised
private- sector entities of the vulnerability. In the week that the
vulnerability was disclosed,

FedCIRC, OMB, and DHS*s National Cyber Security Division held a number of
teleconferences with representatives from the executive branch.

 On July 17, OMB requested that federal agencies report to CERT/ CC on
the status of their actions to patch the vulnerability by July 24.

 On July 18, DHS issued an advisory update in response to an exploit that
was posted online, and OMB moved up the agencies* reporting deadline to
July 22.

CERT/ CC has received reports of attempts to exploit this vulnerability,
but as of September 5, no incidents have yet been reported. Patch
management is a process used to help alleviate many of the challenges
involved with securing computing systems from attack. It is a component of
configuration management 14 that includes acquiring, testing, and applying
patches to a computer system. I will now discuss common

patch management practices, federal efforts to address software
vulnerabilities in agencies, and services and tools to assist in carrying
out the patch management process.

Effective patch management practices have been identified in
securityrelated literature from several groups, including NIST, Microsoft,
15 patch management software vendors, and other computer- security
experts. Common elements identified include the following:

 Senior executive support. Management recognition of information security
risk and interest in taking steps to manage and understand risks,
including ensuring that appropriate patches are deployed, is important to
successfully implementing any information security* related process and
ensuring that appropriate resources are applied. 14 Configuration
management is the control and documentation of changes made to a

system*s hardware, software, and documentation throughout the development
and operational life of a system.

15 Microsoft Corporation, Solutions for Security, Solutions for
Management: The Microsoft Guide to Security Patch Management (Redmond, WA:
2003). Patch Management: A

Critical Process for Mitigating Cyber Vulnerabilities

Common Practices for Effective Patch Management

Page 12 GAO- 03- 1138T  Standardized patch management policies,
procedures, and tools.

Without standardized policies and procedures in place, patch management
can remain an ad- hoc process* potentially allowing each subgroup within
an entity to implement patch management differently or not at all.
Policies provide the foundation for ensuring that requirements are
communicated across an entity. In addition, selecting and implementing
appropriate patch management tools is an important consideration for
facilitating effective and efficient patch management.

 Dedicated resources and clearly assigned responsibilities. It is
important that the organization assign clear responsibility for ensuring
that the patch management process is effective. NIST recommends creating a
designated group whose duties would include supporting administrators in
finding and fixing vulnerabilities in the organization*s software. It is
also important that the individuals involved in patch management have the
skills and knowledge needed to perform their responsibilities, and that
systems administrators be trained regarding how to identify new patches
and vulnerabilities.

 Current technology inventory. Creating and maintaining a current
inventory of all hardware equipment, software packages, services, and
other technologies installed and used by the organization is an essential
element of successful patch management. This systems inventory assists in
determining the number of systems that are vulnerable and require
remediation, as well as in locating the systems and identifying their

 Identification of relevant vulnerabilities and patches. It is important
to proactively monitor for vulnerabilities and patches for all software
identified in the systems inventory. Various tools and services are
available to assist in identifying vulnerabilities and their respective
patches. Using multiple sources can help to provide a more comprehensive
view of vulnerabilities.

 Risk assessment. When a vulnerability is discovered and a related patch
and/ or alternative workaround is released, the entity should consider the
importance of the system to operations, the criticality of the
vulnerability, and the risk of applying the patch. Since some patches can
cause unexpected disruption to entities* systems, organizations may choose
not to apply every patch, at least not immediately, even though it may be
deemed critical by the software vendor that created it. The likelihood
that the patch will disrupt the system is a key factor to consider, as is
the criticality of the system or process that the patch affects.

Page 13 GAO- 03- 1138T  Testing. Another critical step is to test each
individual patch against various systems configurations in a test
environment before installing it

enterprisewide to determine any impact on the network. Such testing will
help determine whether the patch functions as intended and its potential
for adversely affecting the entity*s systems. In addition, while patches
are being tested, organizations should also be aware of workarounds, which
can provide temporary relief until a patch is applied. Testing has been
identified as a challenge by government and private- sector officials,
since the urgency in remediating a security vulnerability can limit or

comprehensive testing. Time pressures can also result in software vendors*
issuing poorly written patches that can degrade system performance and
require yet another patch to remediate the problem. For instance,
Microsoft has admittedly issued security patches that have been recalled
because they have caused systems to crash or are too large for a

computer*s capacity. Further, a complex, heterogeneous systems environment
can lengthen this already time- consuming and time- sensitive process
because it takes longer to test the patch in various systems

 Distributing patches. Organizations can deploy patches to systems
manually or by using an automated tool. One challenge to deploying patches
appropriately is that remote users may not be connected at the time of
deployment, leaving the entity*s networks vulnerable from the remote
user*s system because they have not yet been patched. One privatesector
entity stated that its network first became affected by the Microsoft RPC
vulnerability when remote users plugged their laptops into the network
after being exposed to the vulnerability from other sources.

 Monitoring through network and host vulnerability scanning.

Networks can be scanned on a regular basis to assess the network
environment, and whether patches have been effectively applied. Systems
administrators can take proactive steps to preempt computer security
incidents within their entities by regularly monitoring the status of
patches once they are deployed. This will help to ensure patch compliance
with the network*s configuration. The federal government has taken several
steps to address security

vulnerabilities that affect federal agency systems, including efforts to
improve patch management. NIST has taken a number of steps, including, as
I previously mentioned, providing a handbook for patch management. In
addition, NIST offers a source of vulnerability data, which I will discuss
later in this testimony. Further, in accordance with OMB*s reporting
Federal Efforts to Address

Software Vulnerabilities

Page 14 GAO- 03- 1138T instructions for the first year implementation of
the Federal Information Security Management Act (FISMA), maintaining up-
to- date patches is a

part of FISMA*s system configuration requirements. As such, OMB requires
that agencies report how they confirm that patches have been tested and
installed in a timely manner. 16 In addition, certain governmentwide
services are offered to federal agencies to assist them in ensuring that
software vulnerabilities are patched. For example, FedCIRC was established
to provide a central focal point for incident reporting, handling,
prevention, and recognition for the federal government. Its purpose is to
ensure that the government has critical services available in order to
withstand or quickly recover from attacks against its information

resources. In addition, for the two recent vulnerabilities just discussed
in my testimony, OMB and FedCIRC held teleconferences with agency Chief
information officers to discuss vulnerabilities and request that agencies
report on the status of their actions to patch them. An OMB official
indicated that they planned to hold meetings with agencies to discuss ways
to improve communication of and followup on critical vulnerabilities,
including addressing some of the challenges identified in the two recent
exercises, such as delays in reaching key security personnel in certain

FedCIRC also initiated PADC to provide users with a method of obtaining
information on security patches relevant to their enterprise and access to
patches that have been tested in a laboratory environment. The federal
government offers PADC to federal civilian agencies at no cost. According
to FedCIRC, as of last month, 41 agencies were using PADC. Table 2 lists
its features and benefits, as reported by FedCIRC. OMB reported that while
many agencies have established PADC accounts, actual usage of those
accounts is extremely low.

16 Title III* Federal Information Security Management Act of 2002, E-
Government Act of 2002, P. L. 107- 347, December 17, 2002. This act
superseded an earlier version of FISMA that was enacted as Title X of the
Homeland Security Act of 2002.

Page 15 GAO- 03- 1138T Table 2: Reported Features and Benefits of the
Patch Authentication and Dissemination Capability Features Benefits

 Authorized government users subscribe from a secure Web interface.

 Notifications to subscribers will occur when a patch is available for
subscriber- selected systems or applications.

 Subscribers create customized notification profiles, including operating
systems, firewalls, routers, antivirus software, intrusion- detection
systems, and servers.

 FedCIRC will ensure that the patch originates from a reliable source.

 Subscribers are notified when new threats or vulnerabilities are
discovered; notifications are updated as vendor patches are released and

 FedCIRC will validate that the patch eliminates the intended

 Subscribers may visit a secure site to download validated patches.

 All aspects of the system are secure from subscriber information to the
secure download of patches.

 Subscribers may contact the PADC Help Desk to verify information or to
seek assistance.

 Single consolidated source for all patch updates.

 No cost to federal civilian government agencies. Source: FedCIRC. To
participate in PADC, subscribers (who could be one or more

individuals within an agency) receive an account license that allows them
to receive notifications and log into the secure Web site to download the
patch. To establish an account, each subscriber must set up a profile
defining the technologies that they use. The profiles act much like a
filtering service and allow PADC to notify agencies of only the patches
that pertain to their systems. The profiles do not include system*
specific information because of the sensitivity of that information.
Subscribers using PADC receive notification of threats, vulnerabilities,
and the availability of patches on the basis of the submitted profiles.
They are notified by E- mail or pager message that a vulnerability or
patch has been posted to a secure Web site that affects one or all of
their systems.

When a patch is identified, FedCIRC, through contractor support, ensures
that it originates from a reliable source. The patch is then tested on a
system to which it applies. The installation of the patch and the
operation of the system are monitored to ensure that the patch causes no

Next, if an exploit had been developed, exploit testing is performed to
ensure that the patch fixes the vulnerability. Any issues identified with
a patch are summarized and provided to the users. The validated patch is
then uploaded to PADC servers and made available to users. A patch is
considered validated when it has been downloaded from a trusted source,
authenticated, loaded onto an appropriate system, tested, exploit* tested,
verified, and posted to the PADC server. This type of testing and
validation is performed for over 60 technologies that, according to
FedCIRC officials, account for approximately 80 percent of the
technologies used by federal agencies. Also available is notification of
patches that are not validated for over 25,000 additional technologies.

Page 16 GAO- 03- 1138T According to FedCIRC officials, high- priority
patches are to be tested and posted on the PADC server within the same
business day of availability.

Medium- and low- priority patches are to be completed by the following
business day, but are generally available sooner. However, because PADC
has several early warning mechanisms in place and arrangements with

software vendors, some patches may be available as soon as a vulnerability
is made public. FedCIRC officials emphasize that although the contractor
tests the security patches, these tests do not ensure that the patch can
be successfully deployed in another environment; therefore, agencies still
need to test the patch for compatibility with their own business processes
and technology.

PADC offers a reporting capability that is hierarchical. Senior managers
can look at their complete system and see which subsystems have been
patched. These enterprisewide reports and statistics can be generated for
a *reporting user* subscriber who has read- only capability within the

According to agency officials, there are limitations to the PADC service.
Although it is free to agencies, only about 2,000 licenses or accounts are
available because of monetary constraints. According to FedCIRC officials,
this requires them to work closely with participating agencies to balance
the number of licenses that a single agency requires with the need to
allow multiple agencies to participate. For example, the National
Aeronautics and Space Administration initially requested over 3,000
licenses* one for each system administrator. Another agency, NIST, thought
that each of its users should have his or her own PADC account. Another
limitation is the level of services currently provided by PADC. At

present, the government is considering broadening the scope of these
services and capabilities, along with the number of users.

Several services and automated tools are available to assist entities in
performing the patch management function, including tools designed to be
stand- alone patch management systems. In addition, systems management

tools can be used to deploy patches across an entity*s network. Some of
the features in services and tools typically include methods to

 inventory computers and the software applications and patches installed;
 identify relevant patches and workarounds and gather them in one
location; Services and Tools Also

Provide Means for Improving Patch Management

Page 17 GAO- 03- 1138T  group systems by departments, machine types, or
other logical divisions to easily manage patch deployment;  scan a
network to determine the status of the patches and other

corrections made to network machines (hosts and/ or clients);  assess the
machines against set criteria;  access a database of patches;  test
patches;  deploy effective patches; and

 report information to various levels of management about the status of
the network.

Patch management vendors also offer central databases of the latest
patches, incidents, and methods for mitigating risks before a patch can be
deployed or a patch has been released. Some vendors provide support for
multiple software platforms, such as Microsoft, Solaris, Linux, and
others, while others focus on certain platforms exclusively, such as

Patch management tools can be either scanner* based (non agent) or agent*
based. While scanner* based tools can scan a network, check for missing
patches, and allow an administrator to patch multiple computers, these
tools are best suited for smaller organizations due to their inability to
serve a large number of users without breaking down or requiring major
changes in procedure. Another difficulty with scanner- based tools is that
part- time users and turned- off systems will not be scanned.

Agent- based products place small programs, or agents, on each computer,
to periodically poll a patch database* a server on the network* for new
updates, giving the administrator the option of applying the patch.
Agentbased products require up- front work to integrate agents into the
workstations and in the server deployment process, but are better suited
to large organizations due to their ability to generate less network
traffic and provide a real- time network view. The agents maintain
information that can be reported when needed. Finally, some patch
management tools are hybrids* allowing the user to utilize agents or not.

Instead of an automated stand- alone system, entities can also use other
methods and tools to perform patch management. For example, they can

Page 18 GAO- 03- 1138T maintain a database of the versions and latest
patches for each server and each client in their network and track the
security alerts and patches

manually. While labor- intensive, this can be done. In addition, entities
can employ systems management tools with patch- updating capabilities to
deploy the patches. This method requires monitoring for the latest
security alerts and patches. Entities may also need to develop better
relationships with their vendors to be alerted to vulnerabilities and
patches prior to public release. In addition, software vendors may provide
automated tools with customized features to alert system administrators
and users of the need to patch, and if desired, automatically apply

A variety of resources are also available to provide information related
to vulnerabilities and their exploits. As I mentioned earlier, one
resource is CERT/ CC, a major center for analyzing and reporting
vulnerabilities as well as providing information on possible solutions.
Another useful resource is NIST*s ICAT, which offers a searchable index
leading users to vulnerability resources and patch information. ICAT links
users to publicly available vulnerability databases and patch sites, thus
enabling them to find and fix vulnerabilities existing on their systems.
It is based on common vulnerability and exposures (commonly referred to as
CVE) naming standards. These are standardized names for vulnerabilities
and other information security exposures, compiled in an effort to make it
easier to share data across separate vulnerability databases and tools.

Many other organizations exist, including the Last Stage of Delirium
Research Group, that research security vulnerabilities and maintain
databases of such vulnerabilities. In addition, mailing lists, such as
BugTraq, provide forums for announcing and discussing vulnerabilities,
including information on how to fix them. In addition, Security Focus
monitors thousands of products to maintain a vulnerability database and
provide security alerts. Finally, vendors such as Microsoft and Cisco
provide software updates on their products, including notices of known
vulnerabilities and their corresponding patches.

In addition to implementing effective patch management practices, several
additional steps can be considered when addressing software
vulnerabilities, including:  deploying other technologies, such as
antivirus software, firewalls, and

other network security tools to provide additional defenses against
attacks; Additional Steps That

Can Be Taken

Page 19 GAO- 03- 1138T  employing more rigorous engineering practices in
designing, implementing, and testing software products to reduce the
number of potential vulnerabilities;

 improving tools to more effectively and efficiently manage patching; 
researching and developing technologies to prevent, detect, and recover

from attacks as well as identify their perpetrators, such as more
sophisticated firewalls to keep serious attackers out, better
intrusiondetection systems that can distinguish serious attacks from
nuisance probes and scans, systems that can isolate compromised areas and
reconfigure while continuing to operate, and techniques to identify
individuals responsible for specific incidents; and

 ensuring effective, tested contingency planning processes and
procedures. Actions are already underway in many, if not all, of these
areas. For example, CERT/ CC has a research program, one goal of which is
to try to find ways to improve technical approaches for identifying and
preventing security flaws, for limiting the damage from attacks, and for
ensuring that systems continue to provide essential services in spite of

and failures. Also, Microsoft recently initiated its Trustworthy Computing
strategy to incorporate security- focused software engineering practices
throughout the design and deployment of its software, and is reportedly
considering the use of automated patching in future products.

In summary, it is clear from the increasing number of reported attacks on
information systems that both federal and private- sector operations and
assets are at considerable* and growing* risk. Patch management can be an
important element in mitigating the risks associated with software
vulnerabilities, part of overall network configuration management and
information security programs. The challenge will be ensuring that a patch
management process has adequate resources and appropriate policies,
procedures, and tools to effectively identify vulnerabilities and patches
that place an entity*s systems at risk. Also critical is the capability to
adequately test and deploy the patches, and then monitor progress to
ensure that they work. Although this can currently be performed, the
eventual solution will likely come from research and development to better
build security into software and tools from the beginning.

Mr. Chairman, this concludes my statement. I would be pleased to answer
any questions that you or other members of the Subcommittee may have at

Page 20 GAO- 03- 1138T this time. Should you have any further questions
about this testimony, please contact me at (202) 512- 3317 or at [email protected]
gao. gov.

Individuals making key contributions to this testimony included Shannin G.
Addison, Michael P. Fruitman, Michael W. Gilmore, Sophia Harrison,
Elizabeth L. Johnston, Min S. Lee, and Tracy C. Pierson.


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