Lag exploit

[lunatixxx]

Confirmed cheater use lag exploit on server to the point it is freezing and this did not look like a DDOS it came back in a normal state as soon as he left, but before most players crashed (a mix with spray exploit ?). Can't really help more as there is nothing useful in logs but this need to be adressed quickly.

Already got : // [smac_commands.smx] Amount of commands allowed per second. (0 = Disabled) // - // Default: "20" // Minimum: "0.000000" smac_antispam_cmds "20" (not sure it is safe to go lower)

[lunatixxx]

For the lag exploit i'm not sure how, but i found that when it crashed players: STEAMAUTH: Client received failure code 6 L 10/26/2021 - 01:55:05: "player<1401><STEAM_1:1:>" disconnected (reason "No Steam logon")

I did not crash but i have sprays disabled i guess it is why.

[lunatixxx]

And by the way i had that: https://forums.alliedmods.net/showthread.php?t=323447

So this plugin is pointless, just give the ability to disable sprays server side which does not work by disabling allow_upload and allow_download

[lunatixxx]

You might want to check that, if it is not fixed on CSGO i guess it's the same on L4D2. Apparently the exploit works even with allowdownload and upload on 0.

https://forums.alliedmods.net/showthread.php?p=2656975 https://forums.alliedmods.net/showthread.php?p=2656975

[lunatixxx]

Also there are some dangerous commands (lag/crash) that are still usable in Left 4 dead 2, that are impossible to block or set as a cheat since a certain update of L4D2 where Valve decided to prevent admins to block or change some client commands.

"ai_test_los"
"cl_fullupdate",
"dbghist_addline",                 
"dbghist_dump",                    
"drawcross",                       
"drawline",                        
"dump_entity_sizes",               
"dump_globals",                    
"dump_panels"
"dump_terrain",                    
"dumpcountedstrings",              
"dumpentityfactories",             
"dumpeventqueue",                  
"dumpgamestringtable",             
"editdemo",                        
"endround",                        
"groundlist",                      
"listdeaths",                      
"listmodels",                      
"map_showspawnpoints",             
"mem_dump",                        
"mp_dump_timers",                  
"npc_ammo_deplete",                
"npc_heal",                        
"npc_speakall",                    
"npc_thinknow",                    
"physics_budget",                  
"physics_debug_entity",            
"physics_highlight_active",        
"physics_report_active",           
"physics_select",                  
"report_entities",                 
"report_simthinklist",             
"report_touchlinks",               
"respawn_entities",                
"rr_reloadresponsesystems",        
"scene_flush"
"snd_digital_surround",            
"snd_restart"
"soundlist",                       
"soundscape_flush",                
"sv_benchmark_force_start",        
"sv_findsoundname",                
"sv_soundemitter_filecheck",       
"sv_soundemitter_flush",           
"sv_soundscape_printdebuginfo",    
"wc_update_entity",                
"ping",  

[lunatixxx]

And one more, this could be that: https://forums.alliedmods.net/showthread.php?t=332721

[lunatixxx]

This happened again and my server is fucking very protected, there is a vulnerability in this game for sure. I have a demo of the hacker if you want, but i doubt that it will help. Typical attack where the suspect need to be on the server.

Again please look into that or try to contact the author, as he said he did not patch all exploits for some reasons: https://forums.alliedmods.net/showthread.php?t=332721