OpenSSH sshd session hijacking

openssh-sshd-session-hijacking (41438)

Medium Risk

Description:

OpenSSH could allow a local authenticated attacker to hijack forwarded X11 sessions, caused by an error in sshd when setting the DISPLAY environment variable. By listening to the same port used to forward the X11 session, a local attacker could obtain the MIT-MAGIC-COOKIE and hijack other user's sessions.

Platforms Affected:

• Canonical, Ubuntu 6.06 LTS
• Canonical, Ubuntu 6.10
• Canonical, Ubuntu 7.04
• Canonical, Ubuntu 7.10
• Debian, Debian Linux 4.0
• Gentoo, Linux
• Globus Project and Globus Toolkit, Globus Toolkit 4.0.0 - 4.0.7
• Globus Project and Globus Toolkit, Globus Toolkit 4.1.0 - 4.1.3
• HP, HP-UX B.11.11
• HP, HP-UX B.11.23
• HP, HP-UX B.11.31
• IBM, z OS
• Mandriva, Corporate Server 3.0 X86_64
• Mandriva, Corporate Server 3.0
• Mandriva, Corporate Server 4.0 X86_64
• Mandriva, Corporate Server 4.0
• Mandriva, Linux 2007
• Mandriva, Linux 2007 X86_64
• Mandriva, Linux 2007.1 X86_64
• Mandriva, Linux 2007.1
• Mandriva, Linux 2008.0 X86_64
• Mandriva, Linux 2008.0
• Mandriva, Multi Network Firewall 2.0
• OpenBSD, OpenSSH 4.3p2
• OpenBSD, OpenSSH 4.7p1
• SourceForge, cwsync prior to 2.1.2
• Sun, Solaris 10 SPARC
• Sun, Solaris 10 x86
• Sun, Solaris 9 SPARC
• Sun, Solaris 9 x86

Remedy:

For Globus Toolkit GSI:
Upgrade to the latest version of Globus Toolkit GSI (4.3 or later), available from the GSI-OpenSSH Bundle Web page. See References.

For cwrsync:
Upgrade to the latest version of cwrsync (2.12 or later), available from SourceForge.net. See References.

For other distributions:
Apply the appropriate update for your system. See References.

Consequences:

Other

References:

• Debian Bug report logs - #463011, ssh: unprivileged users may hijack forwarded X connections by listening on port 6010 at http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=463011.
• GSI-OpenSSH Bundle Web page, Downloading the GSI-Enabled OpenSSH Bundle at http://grid.ncsa.uiuc.edu/ssh/download.html.
• HPSBUX02337 SSRT080072 rev.1, HP-UX Running HP-UX Secure Shell, Local Unauthorized Access and Denial of Service (DoS at http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?lang=en&cc=us&objectID=c01462841.
• IBM APAR OA25412, OA25412: DOC UPDATE FOR IBM PORTED TOOLS FOR Z/OS OPENSSH 5655M2301 at http://www-1.ibm.com/support/docview.wss?rs=203&context=SW000&dc=DB550&dc=D100&q1=Security+vulnerability&uid=isg1OA25412.
• OpenSSH Web site , OpenSSH at http://www.openssh.org.
• SourceForge.net, cwrsync at http://sourceforge.net/project/showfiles.php?group_id=69227&package_id=68081.
• Sun Alert ID: 237444, Security Vulnerability in Solaris SSH May Allow Unauthorized Access to X11 Sessions at http://sunsolve.sun.com/search/document.do?assetkey=1-66-237444-1.
• ASA-2008-205: Security Vulnerability in Solaris SSH May Allow Unauthorized Access to X11 Sessions (Sun 237444)
• ASA-2008-229: HPSBUX02337 SSRT080072 rev.1 - HP-UX Running HP-UX Secure Shell Local Unauthorized Access and Denial of Service (DoS)
• BID-28444: OpenSSH X Connections Session Hijacking Vulnerability
• CVE-2008-1483: OpenSSH 4.3p2, and probably other versions, allows local users to hijack forwarded X connections by causing ssh to set DISPLAY to :10, even when another process is listening on the associated port, as demonstrated by opening TCP port 6010 (IPv4) and sniffing a cookie sent by Emacs.
• DSA-1576: openssh -- predictable random number generator
• FrSIRT/ADV-2008-0994: OpenSSH Forwarded X Connection Information Disclosure Vulnerability
• FrSIRT/ADV-2008-1123: Globus Toolkit and GSI-OpenSSH Information Disclosure Issue
• FrSIRT/ADV-2008-1124: cwRsync Security Update Fixes OpenSSH Multiple Local Vulnerabilities
• FrSIRT/ADV-2008-1526: Avaya IR Solaris OpenSSH Information Disclosure Weakness
• FrSIRT/ADV-2008-1624: IBM AIX Security Update Fixes OpenSSH Multiple Local Vulnerabilities
• GLSA-200804-03: OpenSSH: Privilege escalation
• MDVSA-2008:078: Updated openssh packages fix X connection hijacking
• SA29522: OpenSSH X11 Forwarding Information Disclosure Vulnerability
• SA29686: cwRsync OpenSSH Security Bypass and Information Disclosure
• SA29721: Globus Toolkit GSI-OpenSSH Information Disclosure
• SA30086: Sun Solaris SSH X11 Forwarding Vulnerability
• SA30230: Avaya CMS Solaris SSH X11 Forwarding Vulnerability
• SA30347: HP-UX Secure Shell Unauthorized Access Vulnerability
• SECTRACK ID: 1019707: OpenSSH Lets Local Users Hijack Forwarded X Sessions in Certain Cases
• SUSE-SR:2008:009: SUSE Security Summary Report
• USN-597-1: OpenSSH vulnerability

Reported:

Jan 28, 2008

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