Vulnerability Note VU#492558

tcpdump contains integer underflow vulnerability in ISAKMP "Identification Payload" handling

Original Release date: 27 Aug 2004 | Last revised: 27 Aug 2004


A vulnerability in tcpdump could allow a remote attacker to cause a denial of service on an affected system.


The tcpdump tool allows for the inspection of network packets and contains decoders for many standard protocols, including the Internet Security Association and Key Management Protocol (ISAKMP). The ISAKMP "Identification Payload" contains information used for determining the identities of communicating peers and may be used for determining authenticity of information. A flaw exists in the way that tcpdump's ISAKMP decoder handles ISAKMP packets with a malformed Identification Payload. According to the Rapid7 advisory about this issue:

    An ISAKMP packet with a malformed Identification payload with a self-reported payload length that becomes less than 8 when its byte order is reversed will cause TCPDUMP to crash as it tries to read from beyond the end of the snap buffer. TCPDUMP must be using a snaplen of 325 or greater for this underflow to be triggered.

This condition is only exploitable if tcpdump is invoked with the verbose display option, '-v'.


A remote attacker could cause tcpdump to crash.


Apply a patch from the vendor

Patches have been released to address this issue. Please see the Systems Affected section of this document for more details.

Systems Affected (Learn More)

VendorStatusDate NotifiedDate Updated
DebianAffected-26 Aug 2004
Fedora ProjectAffected-26 Aug 2004
Gentoo LinuxAffected-26 Aug 2004
MandrakeSoftAffected-26 Aug 2004
OpenPKGAffected-26 Aug 2004
Red Hat Inc.Affected-26 Aug 2004
SGIAffected-26 Aug 2004
SlackwareAffected-26 Aug 2004
SuSE Inc.Affected-26 Aug 2004
Trustix Secure LinuxAffected-26 Aug 2004
If you are a vendor and your product is affected, let us know.

CVSS Metrics (Learn More)

Group Score Vector
Base N/A N/A
Temporal N/A N/A
Environmental N/A N/A



This vulnerability was discovered by Rapid7 using their Striker test suite.

This document was written by Chad R Dougherty based on information published in Rapid7 Advisory R7-0017.

Other Information

  • CVE IDs: CAN-2004-0184
  • Date Public: 30 Mar 2004
  • Date First Published: 27 Aug 2004
  • Date Last Updated: 27 Aug 2004
  • Severity Metric: 1.69
  • Document Revision: 16


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