RHSA-2017:0641 - Security Advisory

Topic

An update for openssh is now available for Red Hat Enterprise Linux 6.

Red Hat Product Security has rated this update as having a security impact of Moderate. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Description

OpenSSH is an SSH protocol implementation supported by a number of Linux, UNIX, and similar operating systems. It includes the core files necessary for both the OpenSSH client and server.

Security Fix(es):

• It was discovered that the OpenSSH sshd daemon fetched PAM environment settings before running the login program. In configurations with UseLogin=yes and the pam_env PAM module configured to read user environment settings, a local user could use this flaw to execute arbitrary code as root. (CVE-2015-8325)

Additional Changes:

For detailed information on changes in this release, see the Red Hat Enterprise Linux 6.9 Release Notes and Red Hat Enterprise Linux 6.9 Technical Notes linked from the References section.

Solution

For details on how to apply this update, which includes the changes described in this advisory, refer to:

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

After installing this update, the OpenSSH server daemon (sshd) will be restarted automatically.

Affected Products

• Red Hat Enterprise Linux Server 6 x86_64
• Red Hat Enterprise Linux Server 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 i386
• Red Hat Enterprise Linux Workstation 6 x86_64
• Red Hat Enterprise Linux Workstation 6 i386
• Red Hat Enterprise Linux Desktop 6 x86_64
• Red Hat Enterprise Linux Desktop 6 i386
• Red Hat Enterprise Linux for IBM z Systems 6 s390x
• Red Hat Enterprise Linux for Power, big endian 6 ppc64
• Red Hat Enterprise Linux for Scientific Computing 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 6 s390x

Fixes

• BZ - 1218424 - infinite loop, at 100% cpu in ssh if ^Z is pressed at password prompt
• BZ - 1327547 - ssh-copy-id fails with shells unaware of ~/
• BZ - 1328012 - CVE-2015-8325 openssh: privilege escalation via user's PAM environment and UseLogin=yes
• BZ - 1341747 - sftp -m doesn't work as advertised
• BZ - 1353359 - 5.3p1-117.el6 breaks gss-group1-sha1- key exchange algorithm for GSSAPIKeyExchange authentication
• BZ - 1353410 - [ssh-copy-id] add "The agent has no identities." in remote ~/.ssh/authorized_keys
• BZ - 1373836 - Remove RC4 cipher and questionable MACs enabled by default from OpenSSH
• BZ - 1397547 - SSH does not use the ibmca crypto hardware

CVEs

• CVE-2015-8325

References

• https://access.redhat.com/security/updates/classification/#moderate
• https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/6.9_Release_Notes/index.html
• https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/6.9_Technical_Notes/index.html