Vulnerability Note VU#659140

Ethereal ISUP protocol dissector fails to properly decode ISUP packets

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


Ethereal fails to properly decode ISDN User Part (ISUP) packets containing an overly long Interworking Function Address (IWFA) value.


Ethereal is a network traffic analysis package. It includes the ability to decode packets containing ISUP data. There is a vulnerability in the way the ISUP protocol dissector decodes the IWFA value. By sending an ISUP packet containing an overly long IWFA value, a remote, unauthenticated attacker could execute arbitrary code.


A remote, unauthenticated attacker could execute arbitrary code on the vulnerable system.



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 ISUP protocol dissector by performing the following actions in Ethereal:

(for Ethereal versions 0.9.x)

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

(for Ethereal versions 0.10.x)
    1) Select Analyze->Enabled Protocols
    2) Disable the ISUP 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



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: 9.82
  • Document Revision: 10


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