Stefano Di Paola has reported two vulnerabilities in MySQL, which potentially can be exploited by malicious users to compromise a vulnerable system and by malicious, local users to perform certain actions on a vulnerable system with escalated privileges.

1) An input validation error in the "udf_init()" function in "sql_udf.cc" causes the "dl" field of the "mysql.func" table to not be properly sanitised before being used to load libraries. This can be exploited by manipulating the "mysql" administrative database directly via a "INSERT INTO" statement instead of using "CREATE FUNCTION".

Successful exploitation allows loading a malicious library from an arbitrary location, but requires "INSERT" and "DELETE" permissions on the "mysql" administrative database.

NOTE: This can be exploited remotely if a user has privileges to create local files via a "SELECT ... INTO OUTFILE" statement.

2) Temporary files are created insecurely with the "CREATE TEMPORARY TABLE" command and can be exploited via symlink attacks to overwrite arbitrary files with the privileges of MySQL.

The vulnerabilities have been reported in versions 4.0.23, and 4.1.10 and prior.

Solution
The vulnerabilities have been fixed in version 4.0.24 and 4.1.10a.
Further details available to Secunia VIM customers

Provided and/or discovered by
Stefano Di Paola

Changelog
Further details available to Secunia VIM customers

Original Advisory
http://www.wisec.it/vulns.php?page=4
http://www.wisec.it/vulns.php?page=5
http://www.wisec.it/vulns.php?page=6

Deep Links
Links available to Secunia VIM customers