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

ID VU:184030
Type cert
Reporter CERT
Modified 2004-07-12T00:00:00



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.

Systems Affected

Vendor| Status| Date Notified| Date Updated
MySQL| | -| 12 Jul 2004
If you are a vendor and your product is affected, let us know.

CVSS Metrics

Group | Score | Vector
Base | N/A | N/A
Temporal | N/A | N/A
Environmental | N/A | N/A


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This vulnerability was reported by Chris Anley of NGSSoftware .

This document was written by Damon Morda.

Other Information

  • CVE IDs: CAN-2004-0627
  • Date Public: 01 Jul 2004
  • Date First Published: 12 Jul 2004
  • Date Last Updated: 12 Jul 2004
  • Severity Metric: 5.74
  • Document Revision: 26