Computer Associates License Client/Server GETCONFIG Buffer Overflow 

iDEFENSE Security Advisory 03.02.05
www.idefense.com/application/poi/display?id=213&type=vulnerabilities
March 2, 2005

I. 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/

II. 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]

III. 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.

IV. DETECTION

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

V. WORKAROUND

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

VI. 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#a
lp

VII. 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.

VIII. DISCLOSURE TIMELINE

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

IX. CREDIT

An anonymous contributor is credited with discovering this 
vulnerability.

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X. LEGAL NOTICES

Copyright (c) 2005 iDEFENSE, Inc.

Permission is granted for the redistribution of this alert 
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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.