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CERT Coordination Center

GnuTLS Pad Length Denial of Service

Vulnerability Note VU#659209

Original Release Date: 2008-05-30 | Last Revised: 2008-05-30


A vulnerability exists in GnuTLS that may allow a remote attacker to cause a denial of service.


GnuTLS contains a vulnerability in gnults-serv that may result in a denial of service when handling a sequence of specially crafted packets. According to CERT-FI Vulnerability Advisory on GnuTLS:

We have found the flaw by doing complete TLS 1.0 handshake followed by a encrypted Client-Hello message to start abbreviated handshake. In this case the the Record Length field of the TLS Record containing the Client Hello contains erroneus value '8' triggering the bug. Note that this might not be the only way to reproduce the bug.

Note that this issue may affect GnuTLS versions prior to 2.2.5 and also affects version 2.3.0.


A remote, unauthorized attacker may be able to cause a denial of service.


Upgrade or Apply Patch
GnuTLS has issued an upgrade and a patch to address this issue. See GnuTLS Security Advisory SA-2008-01 for more information. GnuTLS is included in various Linux and UNIX distributions. Please consult the relevant documentation of your distribution to obtain the appropriate updates.

Vendor Information


GnuTLS Affected

Updated:  May 30, 2008



Vendor Statement

We have not received a statement from the vendor.

Vendor Information

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


Refer to GnuTLS Security Advisory SA-2008-01 for more information.

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

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This issue was reported in GnuTLS Security Advisory SA-2008-01. GnuTLS credits Ossi Herrala and Jukka Taimisto from the CROSS project at Codenomicon Ltd. for reporting this issue.

This document was written by Chris Taschner.

Other Information

CVE IDs: CVE-2008-1950
Severity Metric: 16.54
Date Public: 2008-05-19
Date First Published: 2008-05-30
Date Last Updated: 2008-05-30 13:41 UTC
Document Revision: 16

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