RHEL 2.1 : vnc (RHSA-2002:287)

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


Synopsis :

The remote Red Hat host is missing one or more security updates.

Description :

Updated VNC packages are available to fix a challenge replay attack
that is present in the VNC server.

VNC is a tool for providing a remote graphical user interface.

The VNC DES authentication scheme is implemented using a
challenge-response architecture, producing a random and different
challenge for each authentication attempt.

A bug in the function for generating the random challenge caused the
random seed to be reset to the current time on every authentication
attempt. As a result, two authentication attempts within the same
second could receive the same challenge. An eavesdropper could exploit
this vulnerability by replaying the response, thereby gaining
authentication.

All users of VNC are advised to upgrade to these errata packages,
which contain an updated version and are not vulnerable to this issue.

Note that when using VNC on an untrusted network, always make sure to
tunnel the VNC protocol through a secure, authenticated channel such
as SSH. Instructions on how to tunnel VNC through SSH are provided at
the following URL: http://www.uk.research.att.com/vnc/sshvnc.html

See also :

https://www.redhat.com/security/data/cve/CVE-2002-1336.html
http://marc.info/?l=bugtraq&m=102753170201524
http://rhn.redhat.com/errata/RHSA-2002-287.html

Solution :

Update the affected vnc, vnc-doc and / or vnc-server packages.

Risk factor :

High / CVSS Base Score : 7.5
(CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P)

Family: Red Hat Local Security Checks

Nessus Plugin ID: 12339 ()

Bugtraq ID:

CVE ID: CVE-2002-1336