FreeBSD VuXML: Documenting security issues in FreeBSD and the FreeBSD Ports Collection

mysql -- mysql_real_connect buffer overflow vulnerability

Affected packages
mysql-server <= 3.23.58_3
4.* <= mysql-server < 4.0.21
mysql-client <= 3.23.58_3
4.* <= mysql-client < 4.0.21


VuXML ID 835256b8-46ed-11d9-8ce0-00065be4b5b6
Discovery 2004-06-04
Entry 2004-12-16
Modified 2005-03-15

The mysql_real_connect function doesn't properly handle DNS replies by copying the IP address into a buffer without any length checking. A specially crafted DNS reply may therefore be used to cause a buffer overflow on affected systems.

Note that whether this issue can be exploitable depends on the system library responsible for the gethostbyname function. The bug finder, Lukasz Wojtow, explaines this with the following words:

In glibc there is a limitation for an IP address to have only 4 bytes (obviously), but generally speaking the length of the address comes with a response for dns query (i know it sounds funny but read rfc1035 if you don't believe). This bug can occur on libraries where gethostbyname function takes length from dns's response


Bugtraq ID 10981
CVE Name CVE-2004-0836