Sever Exploit?

Hello, today i noticed something wierd going on my server.
i had like 4 players that could connect everytime, but when one specefic player join, the Server Crashes without any errors.
I checked the Console and the only thing i noticed was all players that join gets ( IPofPlayer:27005 ) but this one player gets ( HisIP:27006 )
I tought first the port was blocked by the firewall, but its not, all ports are open.

The creepy thing is, the Server doesnt close himself, doesnt give an Error and no Crash Reports, no it just freezes him, you cant type anything in console.
I am using an Windows Server 2012 and never had this problem before it just started when this player connected

I dont know if this is an Exploit to crash servers, im not sure. But i know this guy who gets the diffrent Port, he didnt change anything. The Port changed by itself…
I am really confused cause im not sure if this is an new way to crash servers.

Please give me some tips.

#German English xD

[editline]4th September 2015[/editline]

It could be also just nothing i am not sure :<

Okay, its just this one player seems like its not an Exploit just the player is bugged, but how could it crash the whole server without an error … :open_mouth:

[editline]4th September 2015[/editline]

This exploit is already been on for a “long” time, and is being discussed about, read through it! :3

This player is an friend of me, hes not using this to crash the server, probally he started this exploit by an accident…

Did you try rebooting the server then? Validating files etc?

I try that.

Both.

Mhm, that didnt help no files are corrupted and rebooting doesnt help aswell.
So is it really an Exploit / Hack

Is it only happening when this person connects?

[editline]4th September 2015[/editline]

nevermind

Ask the person to unsubscribe to all addons, and empty the addons folder, then he/she shall try to join(after an full reboot) maybe its an backdoored addon.

It probally started after i installed TDM Cars Ferrari and Lamborghini, I try removing this.

Okay, i fixed it!
The Problem was:
ULX/ULib
The User was bugged somehow in this addon and causes the Server to freeze/crash

It sounds more like an accidental bug than an exploit. Update your ULX/ULib, if the problem continues they are probably conflicting with another addon since they seem to run fine for everyone else.

I reinstalled ULX/Ulib already it works like i said.