Cisco IOS Software TCP Initial Sequence Number Randomization Improvements - Cisco Systems

This script is (C) 2010-2014 Tenable Network Security, Inc.


Synopsis :

The remote device is missing a vendor-supplied security patch

Description :

Cisco IOS Software contains a flaw that permits the successful
prediction of TCP Initial Sequence Numbers.
This vulnerability is present in all released versions of Cisco IOS
software running on Cisco routers and switches. It only affects the
security of TCP connections that originate or terminate on the affected
Cisco device itself
it does not apply to TCP traffic forwarded through
the affected device in transit between two other hosts.
To remove the vulnerability, Cisco is offering free software upgrades
for all affected platforms. The defect is described in DDTS record
CSCds04747.
Workarounds are available that limit or deny successful exploitation
of the vulnerability by filtering traffic containing forged IP source
addresses at the perimeter of a network or directly on individual
devices.

See also :

http://www.nessus.org/u?021e980a
http://www.nessus.org/u?733b0267

Solution :

Apply the relevant patch referenced in Cisco Security Advisory
cisco-sa-20010301-ios-tcp-isn-random.

Risk factor :

High / CVSS Base Score : 7.5
(CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P)
CVSS Temporal Score : 5.5
(CVSS2#E:U/RL:OF/RC:C)
Public Exploit Available : false

Family: CISCO

Nessus Plugin ID: 48953 (cisco-sa-20010301-ios-tcp-isn-randomhttp.nasl)

Bugtraq ID: 2682

CVE ID: CVE-2001-0288