|| ||Pat Riehecky <email@example.com> |
|| ||Security ERRATA Moderate: openssh on SL6.x i386/x86_64 |
|| ||Thu, 28 Feb 2013 16:16:13 -0600|
|| ||Article, Thread
Synopsis: Moderate: openssh security, bug fix and enhancement
Issue Date: 2013-02-21
CVE Numbers: CVE-2012-5536
Due to the way the pam_ssh_agent_auth PAM module was built in Scientific
6, the glibc's error() function was called rather than the intended error()
function in pam_ssh_agent_auth to report errors. As these two functions
different arguments, it was possible for an attacker to cause an application
using pam_ssh_agent_auth to crash, disclose portions of its memory or,
potentially, execute arbitrary code. (CVE-2012-5536)
Note that the pam_ssh_agent_auth module is not used in Scientific Linux 6 by
This update also fixes the following bugs:
* All possible options for the new RequiredAuthentications directive
documented in the sshd_config man page. This update improves the man page to
document all the possible options.
* When stopping one instance of the SSH daemon (sshd), the sshd init script
(/etc/rc.d/init.d/sshd) stopped all sshd processes regardless of the PID
processes. This update improves the init script so that it only kills
with the relevant PID. As a result, the init script now works more
a multi-instance environment.
* Due to a regression, the ssh-copy-id command returned an exit status
zero even if there was an error in copying the key to a remote host.
update, a patch has been applied and ssh-copy-id now returns a non-zero exit
code if there is an error in copying the SSH certificate to a remote host.
* When SELinux was disabled on the system, no on-disk policy was
user account was used for a connection, and no "~/.ssh" configuration was
present in that user's home directory, the SSH client terminated
with a segmentation fault when attempting to connect to another system.
has been provided to address this issue and the crashes no longer occur
* The "HOWTO" document /usr/share/doc/openssh-ldap-5.3p1/HOWTO.ldap-keys
incorrectly documented the use of the AuthorizedKeysCommand directive. This
update corrects the document.
This update also adds the following enhancements:
* When attempting to enable SSH for use with a Common Access Card (CAC), the
ssh-agent utility read all the certificates in the card even though only
certificate was needed. Consequently, if a user entered their PIN
then the CAC was locked, as a match for the PIN was attempted against
certificates. With this update, ssh-add does not try the same PIN for every
certificate if the PIN fails for the first one. As a result, the CAC
be disabled if a user enters their PIN incorrectly.
* This update adds a "netcat mode" to SSH. The "ssh -W host:port ..."
connects standard input and output (stdio) on a client to a single port on a
server. As a result, SSH can be used to route connections via intermediate
* Due to a bug, arguments for the RequiredAuthentications2 directive
stored in a Match block. Consequently, parsing of the config file was not in
accordance with the man sshd_config documentation. This update fixes the bug
and users can now use the required authentication feature to specify a
authentication methods as expected according to the man page.
After installing this update, the OpenSSH server daemon (sshd) will be
- Scientific Linux Development Team
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