A heap-based buffer overflow was found in Mysql. An authenticated database user could use this flaw to cause mysqld to crash or possibly execute arbitrary code with the privileges of the user running mysql.
This issue was assigned CVE-2012-5612
Some other references:
This issue only affect MySQL 5.5 and higher, since the vulnerable MDL subsystem was first implemented in MySQL 5.5:
Based on comment #3, this flaw does not seem to affect the version of mysql shipped with Red Hat Enterprise Linux 5 and 6, since mariadb upstream suggests that this only affects 5.5 and above.
Oracle January 2013 CPU record:
Text of the Oracle flaw description:
Vulnerability in the MySQL Server component of Oracle MySQL (subcomponent: Server Parser). Supported versions that are affected are 5.5.28 and earlier. Easily exploitable vulnerability allows successful authenticated network attacks via multiple protocols. Successful attack of this vulnerability can result in unauthorized Operating System takeover including arbitrary code execution.
Upstream notes this issue only affected MySQL versions 5.5. Red Hat Enterprise Linux 5 and 6 include MySQL versions 5.0.x and 5.1.x respectively, which are not listed as affected. Current Fedora versions are already updated to fixed upstream version. Closing.
Oracle MySQL upstream commits:
MariaDB test case:
The fix is also noted in 5.5.29 release notes:
Very long table aliases in queries could cause the server to exit.