GLSA-200410-29 : PuTTY: Pre-authentication buffer overflow

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


Synopsis :

The remote Gentoo host is missing one or more security-related
patches.

Description :

The remote host is affected by the vulnerability described in GLSA-200410-29
(PuTTY: Pre-authentication buffer overflow)

PuTTY fails to do proper bounds checking on SSH2_MSG_DEBUG packets. The
'stringlen' parameter value is incorrectly checked due to signedness
issues. Note that this vulnerability is similar to the one described in
GLSA 200408-04 but not the same.

Impact :

When PuTTY connects to a server using the SSH2 protocol, an attacker
may be able to send specially crafted packets to the client, resulting
in the execution of arbitrary code with the permissions of the user
running PuTTY. Note that this is possible during the authentication
process but before host key verification.

Workaround :

There is no known workaround at this time.

See also :

http://www.nessus.org/u?f0cf3f40
http://www.chiark.greenend.org.uk/~sgtatham/putty/changes.html
http://www.gentoo.org/security/en/glsa/glsa-200410-29.xml

Solution :

All PuTTY users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose '>=net-misc/putty-0.56'

Risk factor :

Critical / CVSS Base Score : 10.0
(CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C)

Family: Gentoo Local Security Checks

Nessus Plugin ID: 15581 (gentoo_GLSA-200410-29.nasl)

Bugtraq ID:

CVE ID: CVE-2004-1008