MyBB (aka MyBulletinBoard) before 1.4.12 allows remote authenticated users to bypass intended restrictions on the number of [img] MyCodes by editing a post after it has been created.
https://exchange.xforce.ibmcloud.com/vulnerabilities/64518
http://openwall.com/lists/oss-security/2010/12/06/2
http://openwall.com/lists/oss-security/2010/10/11/8
http://openwall.com/lists/oss-security/2010/10/08/7
http://dev.mybboard.net/issues/728
http://blog.mybb.com/2010/04/13/mybb-1-4-12-released-security-maintenance-update/