Rule:
alert ip any any -> any any (msg:"EXPLOIT IGMP IGAP message
overflow attempt"; ip_proto:2; byte_test:1,>,63,0; byte_test:1,<,67,0;
byte_test:1,>,64,13; reference:cve,CAN-2004-0176; reference:bugtraq,9952;
classtype:attempted-admin; sid:2463; rev:1;)

--
Sid:
2463

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Summary:
This event is generated when an attempt is made to exploit a buffer overflow
associated with the Ethereal decode of the Internet Group membership Authentication 
Protocol (IGAP).

--
Impact:
A successful attack may allow the execution of arbitrary code as root or
LOCAL_SYSTEM privilege on a vulnerable host.

--
Detailed Information:
There is a vulnerability associated with particular versions of Ethereal that
may cause a buffer overflow when a malformed IGAP packet is decoded using Ethereal
or tethereal.  This may permit the execution of arbitrary code with root or 
LOCAL_SYSTEM privilege.  The buffer overflow occurs when a larger than expected
Message Size value is discovered in the IGAP payload.

--
Affected Systems:
Any host running Ethereal/tethereal versions 0.10.0 - 0.10.2. 

--
Attack Scenarios:
An attacker can create and send a malformed IGAP packet, and if decoded by
a vulnerable version of Ethereal/tethereal, can cause a buffer overflow and the 
subsequent execution of arbitrary code.

--
Ease of Attack:
Simple. Exploit code is available.

--
False Positives:
None known.

--
False Negatives:
None known.

--
Corrective Action:
Update to version 0.10.3 of Ethereal.

--
Contributors:
Sourcefire Research Team
Judy Novak <judy.novak@sourcefire.com>

--
Additional References

CVE:
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2004-0176

Bugtraq:
http://www.securityfocus.com/bid/9952:

--
