RHBA-2015:1335 - Bug Fix Advisory

Topic

Updated openssh packages that fix several bugs and add various enhancements are
now available for Red Hat Enterprise Linux 6.

Description

OpenSSH is OpenBSD's SSH (Secure Shell) protocol implementation. These packages
include the core files necessary for both the OpenSSH client and server.

Bug fixes:

• Every first attempt to make a connection using the sftp utility, before the

user information was stored in the System Security Services Daemon (SSSD) cache,
failed. The sshd server no longer closes file descriptors before all the user
information is loaded, and sftp connections in combination with SSSD work even
when the SSSD cache is empty. Now, first sftp connection attempts succeed.
(BZ#1085710)

• Printing extensions for v01 certificates using the "ssh-keygen -L -f" command

did not display the certificate extensions correctly. Now, printing extensions
for v01 certificates works as expected. (BZ#1093869)

• The sshd configuration test mode, executed by the "sshd -T" command, did not

display all default options and displayed certain other options incorrectly.
With this update, the sshd test mode outputs all required default options and
also prints the above-mentioned other options correctly. Output of the
configuration test mode can be now safely applied as configuration input.
(BZ#1109251)

• Non-existing users logging in with ssh triggered two different audit messages

in the log, which was not expected behavior. With this update, when a
non-existing user attempts to log in using ssh, only one audit message is
triggered. This message records a login attempt from an unknown user as
expected. (BZ#1127312)

• When the ForceCommand option with a pseudoterminal was used and the MaxSession

option was set to "2", multiplexed ssh connections did not work as expected.
After the user attempted to open a second multiplexed connection, the attempt
failed if the first connection was still open. This update modifies OpenSSH to
issue only one audit message per session. The user is able to open two
multiplexed connections in this situation. (BZ#1131585)

• Previously, OpenSSH did not correctly handle quoted multiple values defined on

one configuration line. When the user specified, for example, multiple groups in
quotes on one line, OpenSSH only honored the first specified group. The OpenSSH
configuration parser has been modified, and OpenSSH honors all option values in
this situation. (BZ#1134938)

• The ssh-copy-id utility failed if the account on the remote server did not use

an sh-like shell. Remote commands have been modified to run in an sh-like shell,
and ssh-copy-id now also works with non-sh-like shells. (BZ#1135521)

• The user could not generate ssh keys on hosts with a host name of 64

characters. The ssh-keygen utility failed in this situation. The buffer size for
host names has been increased, and ssh-keygen no longer fails in the described
situation. (BZ#1161454)

• All the messages obtained from an sftp server when using chroot were logged in

the global log file through the sshd server even when a valid socket for logging
was available. Now, events from the sftp server can be logged through the socket
in chroot and forwarded into an independent log file. (BZ#1172224)

• The ssh-keyscan command did not scan for Elliptic Curve Digital Signature

Algorithm (ECDSA) keys. The "ssh-keyscan -t ecdsa -v localhost" command did not
display any output. The command now outputs the host ECDSA key as expected.
(BZ#1196331)

• This update fixes memory leaks discovered in sshd. (BZ#1208584)

Enhancements:

• This update adds support for adjusting LDAP queries. The administrator can

adjust the LDAP query to obtain public keys from servers that use a different
schema. (BZ#1119506)

• The PermitOpen option in sshd_config file now supports wildcards. (BZ#1159055)
• With this update, openssh can force exact permissions on files that are newly

uploaded using sftp. (BZ#1191055)

Users of openssh are advised to upgrade to these updated packages, which fix
these bugs and add these enhancements.

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

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 from RHUI 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 6 s390x

Fixes

• BZ - 1109251 - sshd -T does not show all (default) options, inconsistency
• BZ - 1127312 - confusing audit trail for unsuccessful logins
• BZ - 1135521 - ssh-copy-id fails with message 'Ambiguous output redirect.' with a non-sh style remote shell
• BZ - 1160487 - Master dies when using -o ProxyCommand
• BZ - 1161449 - ssh client showing Connection closed by UNKNOWN after timeout at password prompt
• BZ - 1161454 - ssh-keygen with error : gethostname: File name too long
• BZ - 1172224 - logging into separate files for chrooted users not possible
• BZ - 1191055 - RFE: option to let openssh/sftp force the exact permissions on newly uploaded files
• BZ - 1197072 - ssh client using HostbasedAuthentication aborts in FIPS mode
• BZ - 1197763 - man ssh doesn't contain ControlPersist option

CVEs

(none)

References

(none)