Facebook Google Plus Twitter LinkedIn YouTube RSS Menu Search Resource - BlogResource - WebinarResource - ReportResource - Eventicons_066 icons_067icons_068icons_069icons_070

OpenSSH < 7.2 X11Forwarding Fallback Bypass Vulnerability

Medium

Synopsis

The remote SSH server may be affected by an X11Forwarding fallback bypass vulnerability.

Description

OpenSSH contains a flaw in ssh(1) that is triggered when it falls back from untrusted X11 forwarding to trusted forwarding when the X server disables the SECURITY extension. This may potentially result in X11 connections not being trusted.

Note: PVS has solely relied on the banner of the SSH client to perform this check. Any backported patches or workarounds such as recompiling or edited configurations are not observable through the banner.

Solution

Upgrade to OpenSSH version 7.2 or later.