PuTTY: Pre-authentication arbitrary code execution

1. Gentoo Linux Security Advisory

Advisory Reference	GLSA 200408-04 / PuTTY
Release Date	August 05, 2004
Latest Revision	May 22, 2006: 03
Impact	normal
Exploitable	remote

Package	Vulnerable versions	Unaffected versions	Architecture(s)
net-misc/putty	<= 0.54	>= 0.55	All supported architectures

Related bugreports: #59383

Synopsis

PuTTY contains a vulnerability allowing a SSH server to execute arbitrary code on the connecting client.

2. Impact Information

Background

PuTTY is a free implementation of Telnet and SSH for Win32 and Unix platforms, along with an xterm terminal emulator.

Description

PuTTY contains a vulnerability allowing a malicious server to execute arbitrary code on the connecting client before host key verification.

Impact

When connecting to a server using the SSH2 protocol an attacker is able to execute arbitrary code with the permissions of the user running PuTTY by sending specially crafted packets to the client during the authentication process but before host key verification.

3. Resolution Information

Workaround

There is no known workaround at this time. All users are encouraged to upgrade to the latest available version of PuTTY.

Resolution

All PuTTY users should upgrade to the latest version:

Code Listing 3.1: Resolution

# emerge sync

# emerge -pv ">=net-misc/putty-0.55"
# emerge ">=net-misc/putty-0.55"

4. References

Page updated August 05, 2004

Summary: This is a Gentoo Linux Security Advisory

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