Bad Company 2 - Username Bug

By Paul

There is a bug in the game that can make playing it online impossible. If a someone connects to a server with a specific style of username then the server lags and it makes the game unplayable until that person (with the bad username) leaves.

The username must be 8 characters long and consist only of 1’s and 0’s.

I tried usernames starting with numbers (1ASDF), starting with multiple numbers (10ASDF) , containing numbers (ASDF2), all numbers but not just 1’s and 0’s (12345).

How this bug came about, a friend of mine routinely uses an alias when playing games that consists of 1’s and 0’s and is 8 digits long. He setup his bad company 2 user account  for the first time at a Lan Party. The moment he connected to the server everyone would lag out. The moment he disconnected the game would go back to normal. At first we never thought the username was the issue because he had earlier issues with his network card not being able to transfer data at a reasonable speed, a cable change and driver upgrade fixed that. We ran WireShark to see if the network traffic changed when he connected and we didn’t notice anything different. Also when he connected someone else in our group and on the same LAN would be disconnected from the game. Another thing that was odd was when we tried to send him a friend request whenever we typed his name (which started with 01) it always added a 1 in front.

We stopped trying to play bad company 2 and moved on to other games. A week or so goes by and he brings up the issue again. He mentioned that he tried changing his name and the game appeared to be working correctly.

That gave me the idea that the game must not be sanitizing some bit of information. Since you aren’t able to run a local server and I am not sure what this bug actually does to the game server (other then lagging everyone), I only did a minimal amount of testing.  I would be very interested to see what’s happening on the server side that’s causing this problem.

I waited until after the bug was fixed before posting this.