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MySQL fails to properly evaluate zero-length strings in the check_scramble_323() function

Vulnerability Note VU#184030

Original Release Date: 2004-07-12 | Last Revised: 2004-07-12


There is a vulnerability in the password authentication mechanism of MySQL which could allow an attacker to bypass authentication by supplying a zero-length string.


MySQL is an open-source database system available for Microsoft Windows, Linux, and other UNIX-based operating systems. There is a vulnerability in the check_scramble_323() function that could allow an attacker to bypass authentication by supplying a "passwd_len" value of NULL. It has been reported that versions 4.1 prior to 4.1.3 and version 5.0 are affected.

Note: In order to exploit this vulnerability, an attacker would have to use a modified MySQL client library.


A remote, unauthenticated attacker with network access to the MySQL server could successfully authenticate without knowledge of the user's password.


According to the NGSSoftware Security Advisory, this vulnerability has been fixed in version 4.1.3 (Beta) and version 5.0 (Alpha).

Note: Users should exercise caution before installing beta or alpha releases.

Restrict access

Block or restrict access to the MySQL service (typically 3306/tcp) from untrusted networks such as the Internet.

Vendor Information


MySQL Affected

Updated:  July 12, 2004



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.


Please refer to the MySQL changelog for version 4.1.3.

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

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This vulnerability was reported by Chris Anley of NGSSoftware.

This document was written by Damon Morda.

Other Information

CVE IDs: CVE-2004-0627
Severity Metric: 5.74
Date Public: 2004-07-01
Date First Published: 2004-07-12
Date Last Updated: 2004-07-12 20:55 UTC
Document Revision: 26

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