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AUSCERT External Security Bulletin Redistribution
ESB-2008.0844 -- [Solaris]
A Regression in the Secure Shell Daemon (sshd(1M)) Breaks
X11 Forwarding Functionality on IPv4 Only Systems
1 September 2008
AusCERT Security Bulletin Summary
Publisher: Sun Microsystems
Operating System: Solaris
Impact: Denial of Service
Access: Existing Account
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Solution Type: Sun Alert
Solution 240906 : A Regression in the Secure Shell Daemon
(sshd(1M)) Breaks X11 Forwarding Functionality on IPv4 Only Systems
Bug ID: 6704823
Solaris 9 Operating System
Solaris 10 Operating System
Date of Workaround Release: 20-Aug-2008
SA Document Body
A regression in the Secure Shell Daemon (sshd(1M)):
The Sun Secure Shell (SSH) patches listed in the "Contributing
Factors" section below break the Secure Shell X11 forwarding feature
on systems with only IPv4 interfaces configured.
2. Contributing Factors
This issue can occur in the following releases:
* Solaris 9 with patch 122300-28 or later
* Solaris 10 with patch 126133-03 or later OR patch 138060-03
* Solaris 9 with patch 122301-28 or later
* Solaris 10 with patch 126134-03 or later OR patch 138061-03
Note 1: Solaris 8 is not impacted by this issue.
Note 2 : Open Solaris installations are not impacted by this issue.
Note3: This issue only affects systems that have only IPv4 interfaces
To determine if a system has only IPv4 interfaces configured the
following command can be run:
$ ifconfig lo0 inet6 || echo "System is affected"
ifconfig: status: SIOCGLIFFLAGS: lo0: no such interface
System is affected
If the described issue occurs, an error message similar to the
following will be seen on the console and in the syslog of the system
being logged into with ssh(1):
Aug 20 11:01:53 solaris sshd: [ID 800047 auth.error] error:
Failed to allocate internet-domain X11 display socket.
Once logged in, the $DISPLAY variable will not be set and X11 programs
will not display on the client system:
$ ssh -X solarishost
Error: Can't open display:
$ echo $DISPLAY
To work around this issue, the following command can be executed as
# ifconfig lo0 inet6 plumb up
Users who are already connected to the host must re-login to use X
Binary Relief is available through normal support channels for Solaris
8 and Solaris 9.
The following T-patches are available through normal support channels
for the following releases:
* Solaris 10 T-patch T138060-04
* Solaris 10 T-patch T138061-04
Note: Removal of the affected patches is not recommended as a
workaround as they resolve a security issue, bug 6684003, as described
in Sun Alert 237444.
A final resolution is pending completion.
This Sun Alert notification is being provided to you on an "AS IS"
basis. This Sun Alert notification may contain information provided by
third parties. The issues described in this Sun Alert notification may
or may not impact your system(s). Sun makes no representations,
warranties, or guarantees as to the information contained herein. ANY
AND ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION
WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR
NON-INFRINGEMENT, ARE HEREBY DISCLAIMED. BY ACCESSING THIS DOCUMENT
YOU ACKNOWLEDGE THAT SUN SHALL IN NO EVENT BE LIABLE FOR ANY DIRECT,
INDIRECT, INCIDENTAL, PUNITIVE, OR CONSEQUENTIAL DAMAGES THAT ARISE
OUT OF YOUR USE OR FAILURE TO USE THE INFORMATION CONTAINED HEREIN.
This Sun Alert notification contains Sun proprietary and confidential
information. It is being provided to you pursuant to the provisions of
your agreement to purchase services from Sun, or, if you do not have
notification may only be used for the purposes contemplated by these
Copyright 2000-2008 Sun Microsystems, Inc., 4150 Network Circle, Santa
Clara, CA 95054 U.S.A. All rights reserved
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