The extended ACL functionality in Cisco IOS 12.2(58)SE2 and 15.0(1)SE discards all lines that end with a log or time keyword, which allows remote attackers to bypass intended access restrictions in opportunistic circumstances by sending network traffic, aka Bug ID CSCts01106.
http://www.securitytracker.com/id?1027005
http://puck.nether.net/pipermail/cisco-nsp/2012-February/083517.html