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Red Hat Enterprise 6: RHSA-2016-0466 Moderate: OpenSSH Auth Bypass

red hat
Calendar Grey March 21, 2016
Scroller Redhat
Important notice regarding enhanced OpenSSH updates addressing vulnerabilities in Red Hat Enterprise Linux. Upgrade suggested.
Updated openssh packages that fix two security issues are now available for Red Hat Enterprise Linux 6

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)
It was discovered that the OpenSSH sshd daemon did not check the list of keyboard-interactive authentication methods for duplicates. A remote attacker could use this flaw to bypass the MaxAuthTries limit, making it easier to perform password guessing attacks. (CVE-2015-5600)
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 security issue Red Hat OpenSSH Linux update Moderate auth bypass

References

https://access.redhat.com/security/cve/CVE-2015-5600 https://access.redhat.com/security/cve/CVE-2016-3115 https://access.redhat.com/security/updates/classification#moderate

Package List

Red Hat Enterprise Linux Desktop (v. 6):
Source: openssh-5.3p1-114.el6_7.src.rpm
i386: openssh-5.3p1-114.el6_7.i686.rpm openssh-askpass-5.3p1-114.el6_7.i686.rpm openssh-clients-5.3p1-114.el6_7.i686.rpm openssh-debuginfo-5.3p1-114.el6_7.i686.rpm openssh-server-5.3p1-114.el6_7.i686.rpm
x86_64: openssh-5.3p1-114.el6_7.x86_64.rpm openssh-askpass-5.3p1-114.el6_7.x86_64.rpm openssh-clients-5.3p1-114.el6_7.x86_64.rpm openssh-debuginfo-5.3p1-114.el6_7.x86_64.rpm openssh-server-5.3p1-114.el6_7.x86_64.rpm
Red Hat Enterprise Linux Desktop Optional (v. 6):
i386: openssh-debuginfo-5.3p1-114.el6_7.i686.rpm openssh-ldap-5.3p1-114.el6_7.i686.rpm pam_ssh_agent_auth-0.9.3-114.el6_7.i686.rpm
x86_64: openssh-debuginfo-5.3p1-114.el6_7.i686.rpm openssh-debuginfo-5.3p1-114.el6_7.x86_64.rpm openssh-ldap-5.3p1-114.el6_7.x86_64.rpm pam_ssh_agent_auth-0.9.3-114.el6_7.i686.rpm pam_ssh_agent_auth-0.9.3-114.el6_7.x86_64.rpm
Red Hat Enterprise Linux HPC Node (v. 6):
Source: openssh-5.3p1-114.el6_7.src.rpm
x86_64: openssh-5.3p1-114.el6_7.x86_64.rpm openssh-clients-5.3p1-114.el6_7.x86_64.rpm openssh-debuginfo-5.3p1-114.el6_7.x86_64.rpm openssh-server-5.3p1-114.el6_7.x86_64.rpm
Red Hat Enterprise Linux HPC Node Optional (v. 6):
x86_64: openssh-askpass-5.3p1-114.el6_7.x86_64.rpm

Read the Full Advisory


Advisory ID: RHSA-2016:0466-01
Product: Red Hat Enterprise Linux
Advisory URL: https://access.redhat.com/errata/RHSA-2016:0466.html
Issue date: 2016-03-21

Topic

Updated openssh packages that fix two security issues are now availablefor Red Hat Enterprise Linux 6.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 security issue Red Hat OpenSSH Linux update Moderate auth bypass

Relevant Releases Architectures

Red Hat Enterprise Linux Desktop (v. 6) - i386, x86_64

Red Hat Enterprise Linux Desktop Optional (v. 6) - i386, x86_64

Red Hat Enterprise Linux HPC Node (v. 6) - x86_64

Red Hat Enterprise Linux HPC Node Optional (v. 6) - x86_64

Red Hat Enterprise Linux Server (v. 6) - i386, ppc64, s390x, x86_64

Red Hat Enterprise Linux Server Optional (v. 6) - i386, ppc64, s390x, x86_64

Red Hat Enterprise Linux Workstation (v. 6) - i386, x86_64

Red Hat Enterprise Linux Workstation Optional (v. 6) - i386, x86_64

Bugs Fixed

1245969 - CVE-2015-5600 openssh: MaxAuthTries limit bypass via duplicates in KbdInteractiveDevices

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

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