Valve has just announced that they rolled out a quick fix to remove the cheats and exploits found in the Xbox 360 version of Left 4 Dead.
As noted, this fixes the issue for dedicated servers on the Xbox 360. Expect another update in the following days to fix it for clients and listen servers.
Valve has released a server-side fix to deny the recently reported cheats on all dedicated Left 4 Dead Xbox 360 servers. The fix is designed to halt the cheating behavior on the dedicated servers, which accounts for the majority of the co-op and Versus modes of play. A title update for those playing on user-hosted servers and/or via system link will be released in the coming days.To those of you who are unaware of the problems, take a look at the following video.
As noted, this fixes the issue for dedicated servers on the Xbox 360. Expect another update in the following days to fix it for clients and listen servers.