191484 2007-09-06 11:06 0000 games-fps/alienarena Format String and DoS vulnerabilities (CVE-2007-475[45]) 2007-09-24 21:32:33 0000 1 1 1 Unclassified Gentoo Security Vulnerabilities unspecified All Linux RESOLVED FIXED http://archives.neohapsis.com/archives/fulldisclosure/2007-09/0049.html ~1 [noglsa] P2 trivial --- 1 mjf@gentoo.org security@gentoo.org games@gentoo.org mjf@gentoo.org 2007-09-06 11:06:34 0000 ---------------------------------------- A] in-game format string in safe_bprintf ---------------------------------------- A format string vulnerability is located in the safe_bprintf function caused by the usage of cprintf without the needed format argument. The bug can be exploited in-game (so with the usual possible password and banning limitations) using a malformed nickname: from game/acesrc/acebot_cmds.c: void safe_bprintf (int printlevel, char *fmt, ...) { int i; char bigbuffer[0x10000]; int len; va_list argptr; edict_t *cl_ent; va_start (argptr,fmt); len = vsprintf (bigbuffer,fmt,argptr); va_end (argptr); if (dedicated->value) gi.cprintf(NULL, printlevel, bigbuffer); for (i=0 ; i<maxclients->value ; i++) { cl_ent = g_edicts + 1 + i; if (!cl_ent->inuse || cl_ent->is_bot) continue; gi.cprintf(cl_ent, printlevel, bigbuffer); } } ------------------------------------------------------- B] clients disconnection through spoofed client_connect ------------------------------------------------------- When queried the game server returns many informations included the list of players which are currently playing and their IP addresses too. Although the Quake 2 protocol isn't prone to spoofing attacks (differently to what happens with Quake 3 and the disconnect packet) here is possible to block and disconnect all the clients which are playing on the server simply using the "client_connect" command. So an attacker needs only to query the server, getting the list of IP:port of the players and sending this command to them using the IP and the port of the server as source. The client will be no longer able to move or send commands in the server and after some minutes it will time out, until this moment it cannot rejoin the same server. ====== 4) Fix ====== No fix. The developer has not been contacted because he is too stupid for understanding a bug report: http://www.quakesrc.org/forums/viewtopic.php?t=6843&start=1 mjf@gentoo.org 2007-09-06 11:10:01 0000 CC'ing herd and setting whiteboard status. rbu@gentoo.org 2007-09-23 16:57:00 0000 CVE assigned CVE-2007-4754 and CVE-2007-4755. Games, please advise. Nico Golde from Debian fixed this issue in [1], the patch is at [2]. [1] http://bugs.debian.org/442075 [2] http://bugs.debian.org/cgi-bin/bugreport.cgi?msg=20;filename=alien-arena_6.05-4_6.05-4.1.patch;att=1;bug=442075 nyhm@gentoo.org 2007-09-24 21:27:33 0000 patched in alienarena-20070613-r1 jaervosz@gentoo.org 2007-09-24 21:32:33 0000 Thx Tristan. Closing with no GLSA.