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Computer Associates License Client/Server GETCONFIG Buffer Overflow

03.02.05

BACKGROUND

The Computer Associates License Client/Server applications provide a
method for CA products to register their licenses on the network. The
License Client and Server are distributed with almost all CA software
distributions. More information about Computer Associates software
products is available from:

   http://www3.ca.com/Products/

DESCRIPTION

Remote exploitation of a buffer overflow vulnerability in Computer
Associates License Server and License Client can allow attackers to
execute arbitrary code.

The vulnerability specifically exists due to insufficient bounds
checking on user-supplied values in GETCONFIG requests. Under normal
operation, the License Server will send a GETCONFIG request to
connecting clients and clients may optionally respond with a similar
GETCONFIG packet. Both the client and server software fail to check
bounds on the last parameter of the GETCONFIG packet which results in a
stack overflow as shown below.

Ollydbg output after SEH overwrite in CA License Server:

EAX 00000001
ECX 7C90FB71 ntdll.7C90FB71
EDX 0000000D
EBX 00E4E053 ASCII "GETCONFIG"
ESP 00E2FC9C
EBP 00E4E050 ASCII "A0"
ESI 00E2FD18
EDI 00E4E05D ASCII "SELF"
EIP DEADC0DE

Log data, item 0
Address=DEADC0DE
Message=Access violation when executing [DEADC0DE]

ANALYSIS

Exploitation allows remote attackers to execute arbitrary code under
the privileges of Local System. The GETCONFIG packet also contains the
remote operating system's version information, which increases the
likelihood of successful exploitation. The CA License Server does not
run by default, but is packaged with most Computer Associates software
distributions. The CA License Client does run by default and is
packaged with almost all Computer Associates software.

DETECTION

iDEFENSE has confirmed that CA License Server 0.1.0.15 and CA License
Client 0.1.0.15 are vulnerable.

WORKAROUND

Use a firewall to only allow trusted hosts to connect to the Computer
Associates License Server and Client ports.

VENDOR RESPONSE

A vendor advisory for this issue is available at:

http://supportconnectw.ca.com/public/ca_common_docs/security_notice.asp

Patches for this issue are available at:

http://supportconnectw.ca.com/public/reglic/downloads/licensepatch.asp#alp

CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CAN-2005-0581 to this issue. This is a candidate for inclusion in
the CVE list (http://cve.mitre.org), which standardizes names for
security problems. This is one of several overflows that have been
assigned CAN-2005-0581.

DISCLOSURE TIMELINE

12/01/2004   Initial vendor notification
12/01/2004   Initial vendor response
03/02/2005   Coordinated public disclosure

CREDIT

An anonymous contributor is credited with discovering this
vulnerability.

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LEGAL NOTICES

Copyright © 2005 Verisign, Inc.

Permission is granted for the redistribution of this alert
electronically. It may not be edited in any way without the express
written consent of iDEFENSE. If you wish to reprint the whole or any
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please email customerservice@idefense.com for permission.

Disclaimer: The information in the advisory is believed to be accurate
at the time of publishing based on currently available information. Use
of the information constitutes acceptance for use in an AS IS
condition. There are no warranties with regard to this information.
Neither the author nor the publisher accepts any liability for any
direct, indirect, or consequential loss or damage arising from use of,
or reliance on, this information.