Secunia

Chris Anley has reported two vulnerabilities in MySQL, allowing malicious people to gain access to the database or the local system.

1) MySQL fails to properly verify passwords if the client has set a specific client capability flag and specifies a "passwd_len" of NULL. This causes MySQL to accept a NULL password as a valid password and authenticates the user.

Successful exploitation requires that the attacker knows a valid username.

2) A boundary error within the handling of "scramble" strings can reportedly be exploited to execute arbitrary code if the attacker knows a password hash or through brute forcing.

The vulnerabilities only affect beta / developement branches of MySQL 4.1.x and MySQL 5.

NOTE: Secunia doesn't recommend installing beta and development software on production systems and doesn't normally issue advisories regarding such software. However, an exception has been made in this case due to the potential attention this issue may receive.

Solution
MySQL production releases 3.x and 4.0.x are not affected.
Further details available in Customer Area

Provided and/or discovered by
Chris Anley, NGSSoftware.

Changelog
Further details available in Customer Area

Original Advisory
http://www.nextgenss.com/advisories/mysql-authbypass.txt

Other references
Further details available in Customer Area

Deep Links
Links available in Customer Area