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Ethereal ISUP protocol dissector fails to properly decode ISUP packets

Vulnerability Note VU#659140

Original Release Date: 2004-03-25 | Last Revised: 2004-03-25


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.

Vendor Information


Ethereal Affected

Updated:  March 25, 2004



Vendor Statement

Please see the Ethereal Security Bulletin at

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.


The CERT/CC has no additional comments at this time.

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

CVSS Metrics

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Ethereal credits Stefan Esser for reporting this vulnerability.

This document was written by Damon Morda.

Other Information

CVE IDs: CVE-2004-0176
Severity Metric: 9.82
Date Public: 2004-03-22
Date First Published: 2004-03-25
Date Last Updated: 2004-03-25 16:55 UTC
Document Revision: 11

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