[CSS/DODS/HL2DM/NMRIH/FFOF] Anti Server Lag Exploits

backwards · **Author**

This plugin attempts to prevent trolls with hacks from lagging the game server which are using internal engine exploits. This wont prevent all lag exploits (such as external-connectionless ones), but it will prevent most of the ones that require a connection to the server to abuse. This is a simple implementation of the function (net_chan_limit_msec) from csgo that valve added which kicks users if the processing time for a packet exceeds a threshold. You control the max milliseconds with the convar `net_chan_limit_msec` which has a default value of 20ms. This may be a little aggressive and can be increased to higher values such as 100 - 150ms if you are having any issues with false client kicks. False kicks can happen due to rare plugins written in a certain way such as a plugin that reads a clients string command for sm_changemap and instantly changes the map in the command callback without a delay. This will run code to load the new bsp file from disk which can have really slow IO depending on your hard drives speed and count towards that users packet processing time.

I wrote a version of this for TF2 which got officially added by valve into tf2 a month later, however there's no guarantee this functionality will be added to older source games any time soon. That's why I created this version to support popular older titles.

That being said, I only tested this in counter-strike source (windows and linux), then cross checked the binarys for other games and the signatures/offsets all matched. Need testers to verify if it's working for the other titles listed or if you are having troll/hacker issues with a game not on this list, I may be able to add support for it.

This plugin requires Dhooks with detour support, this should work fine with sourcemod 1.11 out of the box. Older versions of sourcemod, you will need to download dhooks with detour support extension from here.

ted2020 · *Last edited by ted2020; 12-17-2022 at 03:31.*

Quote:

Originally Posted by backwards

This plugin requires Dhooks with detour support, this should work fine with sourcemod 1.11 out of the box. Older versions of sourcemod, you will need to download dhooks with detour support extension from here.

Haven't tried this yet, but hope it fixes the old voice data overflow issue.

L 12/14/2022 - 02:07:25: [exploit/voicedataexploit.smx] Jack (ID: STEAM_0:1

xxxxxx | IP: xx.xx.xx.xx) was banned for trying to crash the server with voice data overflow. Total packets: 93

Maybe it be nice to be able to ban people that attempts this?

Thanks.

ShigureUi · 12-17-2022 , 07:00 Re: [CSS/DODS/HL2DM/NMRIH/FFOF] Anti Server Lag Exploits

L4d2 support needed.

backwards · 12-17-2022 , 09:21 Re: [CSS/DODS/HL2DM/NMRIH/FFOF] Anti Server Lag Exploits

Quote:

Originally Posted by ShigureUi

L4d2 support needed.

The L4D2 base game already added the convar for this feature natively.

Quote:

Originally Posted by ted2020

Haven't tried this yet, but hope it fixes the old voice data overflow issue.

L 12/14/2022 - 02:07:25: [exploit/voicedataexploit.smx] Jack (ID: STEAM_0:1xxxxxx | IP: xx.xx.xx.xx) was banned for trying to crash the server with voice data overflow. Total packets: 93

Maybe it be nice to be able to ban people that attempts this?

Thanks.

This is probably the only thing it wont prevent since those packets message types are not processed on the servers end and wont cause lag server-side. They are just mirrored to other clients that can hear your voice comunications. I did write an anti voice overflow for css a few years ago but it looks like you already have a plugin for that?

Quote:

[exploit/voicedataexploit.smx]

ted2020 · *Last edited by ted2020; 12-20-2022 at 02:22.*

Quote:

Originally Posted by backwards

The L4D2 base game already added the convar for this feature natively.

This is probably the only thing it wont prevent since those packets message types are not processed on the servers end and wont cause lag server-side. They are just mirrored to other clients that can hear your voice comunications. I did write an anti voice overflow for css a few years ago but it looks like you already have a plugin for that?

Ahhh right. Yeah, that's the one I'm currently using. Only problem I'm facing is that it seems there's a weird script error so it doesn't actually ban or kick the person, but just fills up the voicecrash file with:

PHP Code:


			
L 12/14/2022 - 02:07:25: [exploit/voicedataexploit.smx] Jack (ID: STEAM_0:1:742376174 | IP: 89.39.107.201) was banned for trying to crash the server with voice data overflow. Total packets: 93
L 12/14/2022 - 02:07:25: [exploit/voicedataexploit.smx] Jack (ID: STEAM_0:1:742376174 | IP: 89.39.107.201) was banned for trying to crash the server with voice data overflow. Total packets: 94
L 12/14/2022 - 02:07:25: [exploit/voicedataexploit.smx] Jack (ID: STEAM_0:1:742376174 | IP: 89.39.107.201) was banned for trying to crash the server with voice data overflow. Total packets: 95
L 12/14/2022 - 02:07:25: [exploit/voicedataexploit.smx] Jack (ID: STEAM_0:1:742376174 | IP: 89.39.107.201) was banned for trying to crash the server with voice data overflow. Total packets: 96
L 12/14/2022 - 02:07:25: [exploit/voicedataexploit.smx] Jack (ID: STEAM_0:1:742376174 | IP: 89.39.107.201) was banned for trying to crash the server with voice data overflow. Total packets: 97
L 12/14/2022 - 02:07:25: [exploit/voicedataexploit.smx] Jack (ID: STEAM_0:1:742376174 | IP: 89.39.107.201) was banned for trying to crash the server with voice data overflow. Total packets: 98
L 12/14/2022 - 02:07:25: [exploit/voicedataexploit.smx] Jack (ID: STEAM_0:1:742376174 | IP: 89.39.107.201) was banned for trying to crash the server with voice data overflow. Total packets: 99
L 12/14/2022 - 02:07:25: [exploit/voicedataexploit.smx] Jack (ID: STEAM_0:1:742376174 | IP: 89.39.107.201) was banned for trying to crash the server with voice data overflow. Total packets: 100
L 12/14/2022 - 02:07:25: [exploit/voicedataexploit.smx] Jack (ID: STEAM_0:1:742376174 | IP: 89.39.107.201) was banned for trying to crash the server with voice data overflow. Total packets: 101
L 12/14/2022 - 02:07:25: [exploit/voicedataexploit.smx] Jack (ID: STEAM_0:1:742376174 | IP: 89.39.107.201) was banned for trying to crash the server with voice data overflow. Total packets: 102

and so on.

and latest I get this:

PHP Code:


			
L 12/16/2022 - 22:41:12: [exploit/voicedataexploit.smx] RattlesnK (ID: STEAM_ID_STOP_IGNORING_RETVALS | IP: 89.187.185.171) was banned for trying to crash the server with voice data overflow. Total packets: 11821
L 12/16/2022 - 22:41:12: [exploit/voicedataexploit.smx] RattlesnK (ID: STEAM_ID_STOP_IGNORING_RETVALS | IP: 89.187.185.171) was banned for trying to crash the server with voice data overflow. Total packets: 11822
L 12/16/2022 - 22:41:12: [exploit/voicedataexploit.smx] RattlesnK (ID: STEAM_ID_STOP_IGNORING_RETVALS | IP: 89.187.185.171) was banned for trying to crash the server with voice data overflow. Total packets: 11823
L 12/16/2022 - 22:41:12: [exploit/voicedataexploit.smx] RattlesnK (ID: STEAM_ID_STOP_IGNORING_RETVALS | IP: 89.187.185.171) was banned for trying to crash the server with voice data overflow. Total packets: 11824
L 12/16/2022 - 22:41:12: [exploit/voicedataexploit.smx] RattlesnK (ID: STEAM_ID_STOP_IGNORING_RETVALS | IP: 89.187.185.171) was banned for trying to crash the server with voice data overflow. Total packets: 11825
L 12/16/2022 - 22:41:12: [exploit/voicedataexploit.smx] RattlesnK (ID: STEAM_ID_STOP_IGNORING_RETVALS | IP: 89.187.185.171) was banned for trying to crash the server with voice data overflow. Total packets: 11826
L 12/16/2022 - 22:41:12: [exploit/voicedataexploit.smx] RattlesnK (ID: STEAM_ID_STOP_IGNORING_RETVALS | IP: 89.187.185.171) was banned for trying to crash the server with voice data overflow. Total packets: 11827
L 12/16/2022 - 22:41:12: [exploit/voicedataexploit.smx] RattlesnK (ID: STEAM_ID_STOP_IGNORING_RETVALS | IP: 89.187.185.171) was banned for trying to crash the server with voice data overflow. Total packets: 11828

Guess I need to have a look at the script again. Thanks tho

Franc1sco · 12-20-2022 , 13:52 Re: [CSS/DODS/HL2DM/NMRIH/FFOF] Anti Server Lag Exploits

Quote:

Originally Posted by ted2020

Ahhh right. Yeah, that's the one I'm currently using. Only problem I'm facing is that it seems there's a weird script error so it doesn't actually ban or kick the person, but just fills up the voicecrash file with:

PHP Code:


			
L 12/14/2022 - 02:07:25: [exploit/voicedataexploit.smx] Jack (ID: STEAM_0:1:742376174 | IP: 89.39.107.201) was banned for trying to crash the server with voice data overflow. Total packets: 93

L 12/14/2022 - 02:07:25: [exploit/voicedataexploit.smx] Jack (ID: STEAM_0:1:742376174 | IP: 89.39.107.201) was banned for trying to crash the server with voice data overflow. Total packets: 94

L 12/14/2022 - 02:07:25: [exploit/voicedataexploit.smx] Jack (ID: STEAM_0:1:742376174 | IP: 89.39.107.201) was banned for trying to crash the server with voice data overflow. Total packets: 95

L 12/14/2022 - 02:07:25: [exploit/voicedataexploit.smx] Jack (ID: STEAM_0:1:742376174 | IP: 89.39.107.201) was banned for trying to crash the server with voice data overflow. Total packets: 96

L 12/14/2022 - 02:07:25: [exploit/voicedataexploit.smx] Jack (ID: STEAM_0:1:742376174 | IP: 89.39.107.201) was banned for trying to crash the server with voice data overflow. Total packets: 97

L 12/14/2022 - 02:07:25: [exploit/voicedataexploit.smx] Jack (ID: STEAM_0:1:742376174 | IP: 89.39.107.201) was banned for trying to crash the server with voice data overflow. Total packets: 98

L 12/14/2022 - 02:07:25: [exploit/voicedataexploit.smx] Jack (ID: STEAM_0:1:742376174 | IP: 89.39.107.201) was banned for trying to crash the server with voice data overflow. Total packets: 99

L 12/14/2022 - 02:07:25: [exploit/voicedataexploit.smx] Jack (ID: STEAM_0:1:742376174 | IP: 89.39.107.201) was banned for trying to crash the server with voice data overflow. Total packets: 100

L 12/14/2022 - 02:07:25: [exploit/voicedataexploit.smx] Jack (ID: STEAM_0:1:742376174 | IP: 89.39.107.201) was banned for trying to crash the server with voice data overflow. Total packets: 101

L 12/14/2022 - 02:07:25: [exploit/voicedataexploit.smx] Jack (ID: STEAM_0:1:742376174 | IP: 89.39.107.201) was banned for trying to crash the server with voice data overflow. Total packets: 102

and so on.

and latest I get this:

PHP Code:


			
L 12/16/2022 - 22:41:12: [exploit/voicedataexploit.smx] RattlesnK (ID: STEAM_ID_STOP_IGNORING_RETVALS | IP: 89.187.185.171) was banned for trying to crash the server with voice data overflow. Total packets: 11821

L 12/16/2022 - 22:41:12: [exploit/voicedataexploit.smx] RattlesnK (ID: STEAM_ID_STOP_IGNORING_RETVALS | IP: 89.187.185.171) was banned for trying to crash the server with voice data overflow. Total packets: 11822

L 12/16/2022 - 22:41:12: [exploit/voicedataexploit.smx] RattlesnK (ID: STEAM_ID_STOP_IGNORING_RETVALS | IP: 89.187.185.171) was banned for trying to crash the server with voice data overflow. Total packets: 11823

L 12/16/2022 - 22:41:12: [exploit/voicedataexploit.smx] RattlesnK (ID: STEAM_ID_STOP_IGNORING_RETVALS | IP: 89.187.185.171) was banned for trying to crash the server with voice data overflow. Total packets: 11824

L 12/16/2022 - 22:41:12: [exploit/voicedataexploit.smx] RattlesnK (ID: STEAM_ID_STOP_IGNORING_RETVALS | IP: 89.187.185.171) was banned for trying to crash the server with voice data overflow. Total packets: 11825

L 12/16/2022 - 22:41:12: [exploit/voicedataexploit.smx] RattlesnK (ID: STEAM_ID_STOP_IGNORING_RETVALS | IP: 89.187.185.171) was banned for trying to crash the server with voice data overflow. Total packets: 11826

L 12/16/2022 - 22:41:12: [exploit/voicedataexploit.smx] RattlesnK (ID: STEAM_ID_STOP_IGNORING_RETVALS | IP: 89.187.185.171) was banned for trying to crash the server with voice data overflow. Total packets: 11827

L 12/16/2022 - 22:41:12: [exploit/voicedataexploit.smx] RattlesnK (ID: STEAM_ID_STOP_IGNORING_RETVALS | IP: 89.187.185.171) was banned for trying to crash the server with voice data overflow. Total packets: 11828

Guess I need to have a look at the script again. Thanks tho

Maybe its for the flood of the sm_ban command, I made some improvements to the plugin (like just use one time the punish command) and released here if you want to try it. Also for STEAM_ID_STOP_IGNORING_RETVALS steamids it will not ban, so probably it need to be kicked instead, try to change the punishment to kick. I also added a logic where automatic kick players with invalid id using the exploit.

ted2020 · 12-23-2022 , 02:54 Re: [CSS/DODS/HL2DM/NMRIH/FFOF] Anti Server Lag Exploits

Quote:

Originally Posted by Franc1sco

Maybe its for the flood of the sm_ban command, I made some improvements to the plugin (like just use one time the punish command) and released here if you want to try it. Also for STEAM_ID_STOP_IGNORING_RETVALS steamids it will not ban, so probably it need to be kicked instead, try to change the punishment to kick. I also added a logic where automatic kick players with invalid id using the exploit.

Thanks! Good work.

JLmelenchon · *Last edited by JLmelenchon; 06-29-2023 at 23:41.*

Yes they added it to L4D2 but it is broken and kick innocent players... and this thing is really needed as there are plenty of lag exploits on this game.