Josh Berkus and Tom Lane discovered that MySQL 4.1, a popular SQL database, incorrectly parses a string escaped with mysql_real_escape() which could lead to SQL injection. This problem does only exist in versions 4.1 and 5.0.
The old stable distribution (woody) is not affected by this problem.
For the stable distribution (sarge) this problem has been fixed in version 4.1.11a-4sarge4.
For the unstable distribution (sid) this problem has been fixed in version 5.0.21-4.
Version 4.0 in the stable distribution (sarge) is also not affected by this problem.
We recommend that you upgrade your mysql packages.