L4D2 lag exploit?
 

I have a l4d2 coop server and recently there have been some huge lags happening in the server at random points throughout the day. what happens is the server will lag very hard and become overloaded, then in the console this is spammed very quickly
This doesnt look like a ddos attack but more like a server/game exploit, has this happened to anyone else or has anyone got further information on this. I have seen that valve released an update recently with a patch relating to network packets, but I dont think this has done anything infact it seems to have made the issue worse. Anyway to contact the developers about this?

Re: L4D2 lag exploit?
 

Have you tried steam forums?

Re: L4D2 lag exploit?
 

you can try reporting through Hacker One
probably would need the "steps" to reproduce as well

Re: L4D2 lag exploit?
 

DDOS/DOS attacks are out of scope for valves hackerone program

Re: L4D2 lag exploit?
 

It's not ddos/dos, it's engine's vulnerabilities, you can even use an exe program to attack.
now, the vulnerabilities has been fixed by game update.

Re: L4D2 lag exploit?
 

That's exactly what it is, an engine vulnerability that allows for a DOS attack. That's out of scope, I've already reported several issues like this before and they all get denied/closed for being out of scope. You use exe programs to attack any server when trying to DOS.

Re: L4D2 lag exploit?
 

Yes with the latest L4D2 update this no longer happens, it seems like someone was using an exe or tool to attack servers as it only happens when server gets full. But people have found a new exploit where they can freeze a server and crash it using external tool, can only wait for valve to fix, i have no idea why people are so serious about ddosing and crashing servers in such an old game :(

Re: L4D2 lag exploit?
 

It's because they are weak with poor morals and want to make themselves feel better by being able to cause something that affects 100's of people in a negative way. They think they are smart by finding the easiest of exploits to abuse on servers that do nothing about the issue. When in reality they are unable to find any real exploits that crash servers or cause remote code execution. They are only capable of finding server laggers which the source engine has hundreds of exploitable methods to abuse.