WU-FTPD S/KEY Authentication ftpd.c skey_challenge Function Remote Overflow

This script is Copyright (C) 2004-2014 Tenable Network Security, Inc.


Synopsis :

The remote FTP server seems to be vulnerable to a remote buffer overflow.

Description :

This version of WU-FTPD contains a remote overflow if s/key support is enabled.
The skey_challenge function fails to perform bounds checking on the
name variable resulting in a buffer overflow.
With a specially crafted request, an attacker can execute arbitrary
code resulting in a loss of integrity and/or availability.

It appears that this vulnerability may be exploited prior to authentication.
It is reported that S/Key support is not enabled by default,
though some operating system distributions which ship WU-FTPD may have it
enabled.

*** Nessus solely relied on the banner of the remote server
*** to issue this warning, so it may be a false positive.

See also :

http://www.securiteam.com/unixfocus/6X00Q1P8KC.html

Solution :

Upgrade to WU-FTPD 2.6.3 when available or disable SKEY or apply the
patches available at http://www.wu-ftpd.org

Risk factor :

Critical / CVSS Base Score : 10.0
(CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C)
CVSS Temporal Score : 7.4
(CVSS2#E:U/RL:OF/RC:C)
Public Exploit Available : false

Family: FTP

Nessus Plugin ID: 14372 ()

Bugtraq ID: 8893

CVE ID: CVE-2004-0185