Vulnerability Assessment & Network Security Forums

If through a vulnerability assessment, a network security issue is detected for the vulnerability below, applying the appropriate security patches in a timely matter is very important. If you have detected that your system has already been compromised, following CERT's Network Security recovery document will assist with recommended steps for system recovery.

Home >> Browse Vulnerability Assessment Database >> Gentoo Local Security Checks >> [GLSA-200410-29] PuTTY: Pre-authentication buffer overflow

Vulnerability Assessment Details

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

Vulnerability Assessment Summary
PuTTY: Pre-authentication buffer overflow

Detailed Explanation for this Vulnerability Assessment
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, a possible hacker 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.

References:
http://www.idefense.com/application/poi/display?id=155
http://www.chiark.greenend.org.uk/~sgtatham/putty/changes.html

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

Network Security Threat Level: Medium

Networks Security ID:

Vulnerability Assessment Copyright: (C) 2005 Michel Arboi

Cables, Connectors