Vulnerability Note VU#931588

Ethereal fails to properly decode BGP packets containing MPLS IPv6 labels

Original Release date: 25 Mar 2004 | Last revised: 25 Mar 2004

Overview

Ethereal contains a vulnerability in the way the Border Gateway Protocol (BGP) protocol dissector decodes Multiprotocol Label Switching (MPLS) IPv6 labels.

Description

Ethereal is a network traffic analysis package. It includes the ability to decode packets containing BGP data. According to RFC3031, an MPLS label is an identifier used to represent the Forwarding Equivalence Class (FEC) to which that packet is assigned. There is a buffer overflow vulnerability in the way the BGP protocol dissector decodes MPLS IPv6 labels.

According to the e-matters Security Advisory:

    When parsing a BGP Packet with a MPLS IPv6 label up to 13 bytes on the stack may be overwritten with arbitrary data. Due to the stacklayout exploitability seems unlikly and was therefore not tested.

Impact

A remote, unauthenticated attacker could cause Ethereal to crash or potentially execute code of the attacker's choice.

Solution

Upgrade
Upgrade to version 0.10.3 or later.

Note: Ethereal is considered BETA software at this time.

Disable Dissector

If you are unable to upgrade to version 0.10.3 or later, you can disable the BGP protocol dissector by performing the following actions in Ethereal:

(for Ethereal versions 0.8.x and 0.9.x)

    1) Select Edit->Protocols
    2) Deselect the BGP protocol dissector from the list

(for Ethereal versions 0.10.x)
    1) Select Analyze->Enabled Protocols
    2) Disable the BGP protocol dissector from the list by unchecking its "Status" checkbox

However, it is strongly encouraged to upgrade to version 0.10.3 or later.

Systems Affected (Learn More)

VendorStatusDate NotifiedDate Updated
EtherealAffected-25 Mar 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

References

Credit

Ethereal credits Stefan Esser for reporting this vulnerability.

This document was written by Damon Morda.

Other Information

  • CVE IDs: CAN-2004-0176
  • Date Public: 22 Mar 2004
  • Date First Published: 25 Mar 2004
  • Date Last Updated: 25 Mar 2004
  • Severity Metric: 2.89
  • Document Revision: 10

Feedback

If you have feedback, comments, or additional information about this vulnerability, please send us email.