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Red Hat: RHSA-2016:0465 Moderate: OpenSSH X11 Forwarding Issue

red hat
Calendar Grey March 21, 2016
Scroller Redhat
Revised OpenSSH versions for Red Hat Enterprise Linux tackle moderate security vulnerabilities concerning X11 forwarding functionalities.
Updated openssh packages that fix two security issues are now available for Red Hat Enterprise Linux 7

Solution

Before applying this update, make sure all previously released errata relevant to your system have been applied.

For details on how to apply this update, refer to:

https://access.redhat.com/articles/11258

Summary

OpenSSH is OpenBSD's SSH (Secure Shell) protocol implementation. These packages include the core files necessary for both the OpenSSH client and server.
It was discovered that the OpenSSH server did not sanitize data received in requests to enable X11 forwarding. An authenticated client with restricted SSH access could possibly use this flaw to bypass intended restrictions. (CVE-2016-3115)
An access flaw was discovered in OpenSSH; the OpenSSH client did not correctly handle failures to generate authentication cookies for untrusted X11 forwarding. A malicious or compromised remote X application could possibly use this flaw to establish a trusted connection to the local X server, even if only untrusted X11 forwarding was requested. (CVE-2016-1908)
All openssh users are advised to upgrade to these updated packages, which contain backported patches to correct these issues. After installing this update, the OpenSSH server daemon (sshd) will be restarted automatically.

Topics%20covered

Topics Covered

security advisory moderate Red Hat security fix authentication issue openssh X11 forwarding

References

https://access.redhat.com/security/cve/CVE-2016-1908 https://access.redhat.com/security/cve/CVE-2016-3115 https://access.redhat.com/security/updates/classification#moderate

Package List

Red Hat Enterprise Linux Client (v. 7):
Source: openssh-6.6.1p1-25.el7_2.src.rpm
x86_64: openssh-6.6.1p1-25.el7_2.x86_64.rpm openssh-askpass-6.6.1p1-25.el7_2.x86_64.rpm openssh-clients-6.6.1p1-25.el7_2.x86_64.rpm openssh-debuginfo-6.6.1p1-25.el7_2.x86_64.rpm openssh-keycat-6.6.1p1-25.el7_2.x86_64.rpm openssh-server-6.6.1p1-25.el7_2.x86_64.rpm
Red Hat Enterprise Linux Client Optional (v. 7):
x86_64: openssh-debuginfo-6.6.1p1-25.el7_2.i686.rpm openssh-debuginfo-6.6.1p1-25.el7_2.x86_64.rpm openssh-ldap-6.6.1p1-25.el7_2.x86_64.rpm openssh-server-sysvinit-6.6.1p1-25.el7_2.x86_64.rpm pam_ssh_agent_auth-0.9.3-9.25.el7_2.i686.rpm pam_ssh_agent_auth-0.9.3-9.25.el7_2.x86_64.rpm
Red Hat Enterprise Linux ComputeNode (v. 7):
Source: openssh-6.6.1p1-25.el7_2.src.rpm
x86_64: openssh-6.6.1p1-25.el7_2.x86_64.rpm openssh-clients-6.6.1p1-25.el7_2.x86_64.rpm openssh-debuginfo-6.6.1p1-25.el7_2.x86_64.rpm openssh-keycat-6.6.1p1-25.el7_2.x86_64.rpm openssh-server-6.6.1p1-25.el7_2.x86_64.rpm
Red Hat Enterprise Linux ComputeNode Optional (v. 7):
x86_64: openssh-askpass-6.6.1p1-25.el7_2.x86_64.rpm openssh-debuginfo-6.6.1p1-25.el7_2.i686.rpm openssh-debuginfo-6.6.1p1-25.el7_2.x86_64.rpm openssh-ldap-6.6.1p1-25.el7_2.x86_64.rpm openssh-server-sysvinit-6.6.1p1-25.el7_2.x86_64.rpm

Read the Full Advisory


Advisory ID: RHSA-2016:0465-01
Product: Red Hat Enterprise Linux
Advisory URL: https://access.redhat.com/errata/RHSA-2016:0465.html
Issue date: 2016-03-21

Topic

Updated openssh packages that fix two security issues are now availablefor Red Hat Enterprise Linux 7.Red Hat Product Security has rated this update as having Moderate securityimpact. Common Vulnerability Scoring System (CVSS) base scores, which givedetailed severity ratings, are available for each vulnerability from theCVE links in the References section.

Topics%20covered

Topics Covered

security advisory moderate Red Hat security fix authentication issue openssh X11 forwarding

Relevant Releases Architectures

Red Hat Enterprise Linux Client (v. 7) - x86_64

Red Hat Enterprise Linux Client Optional (v. 7) - x86_64

Red Hat Enterprise Linux ComputeNode (v. 7) - x86_64

Red Hat Enterprise Linux ComputeNode Optional (v. 7) - x86_64

Red Hat Enterprise Linux Server (v. 7) - ppc64, ppc64le, s390x, x86_64

Red Hat Enterprise Linux Server Optional (v. 7) - ppc64, ppc64le, s390x, x86_64

Red Hat Enterprise Linux Workstation (v. 7) - x86_64

Red Hat Enterprise Linux Workstation Optional (v. 7) - x86_64

Bugs Fixed

1298741 - CVE-2016-1908 openssh: possible fallback from untrusted to trusted X11 forwarding

1316829 - CVE-2016-3115 openssh: missing sanitisation of input for X11 forwarding

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