RHSA-2007:0540 - Security Advisory

Topic

Updated openssh packages that fix a security issue and various bugs are now
available.

This update has been rated as having moderate security impact by the Red Hat
Security Response Team.

Description

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

A flaw was found in the way the ssh server wrote account names to the audit
subsystem. An attacker could inject strings containing parts of audit
messages, which could possibly mislead or confuse audit log parsing tools.
(CVE-2007-3102)

A flaw was found in the way the OpenSSH server processes GSSAPI
authentication requests. When GSSAPI authentication was enabled in the
OpenSSH server, a remote attacker was potentially able to determine if a
username is valid. (CVE-2006-5052)

The following bugs in SELinux MLS (Multi-Level Security) support has also
been fixed in this update:

• It was sometimes not possible to select a SELinux role and level when

logging in using ssh.

• If the user obtained a non-default SELinux role or level, the role change

was not recorded in the audit subsystem.

• In some cases, on labeled networks, sshd allowed logins from level ranges

it should not allow.

The updated packages also contain experimental support for using private
keys stored in PKCS#11 tokens for client authentication. The support is
provided through the NSS (Network Security Services) library.

All users of openssh should upgrade to these updated packages, which
contain patches to correct these issues.

Solution

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

This update is available via Red Hat Network. Details on how to use
the Red Hat Network to apply this update are available at
http://kbase.redhat.com/faq/FAQ_58_10188

Affected Products

• Red Hat Enterprise Linux Server 5 x86_64
• Red Hat Enterprise Linux Server 5 ia64
• Red Hat Enterprise Linux Server 5 i386
• Red Hat Enterprise Linux Workstation 5 x86_64
• Red Hat Enterprise Linux Workstation 5 i386
• Red Hat Enterprise Linux Desktop 5 x86_64
• Red Hat Enterprise Linux Desktop 5 i386
• Red Hat Enterprise Linux for IBM z Systems 5 s390x
• Red Hat Enterprise Linux for Power, big endian 5 ppc
• Red Hat Enterprise Linux Server from RHUI 5 x86_64
• Red Hat Enterprise Linux Server from RHUI 5 i386

Fixes

• BZ - 227733 - [LSPP] unable to ssh into a system as root/auditadm_r
• BZ - 229278 - LSPP: ssh-mls allows a level through that it should not
• BZ - 231695 - LSPP: user unable to ssh to system with user/role/level context
• BZ - 234638 - CVE-2006-5052 GSSAPI information leak
• BZ - 234951 - [LSPP] openssh server fails to parse level correctly
• BZ - 248059 - CVE-2007-3102 audit logging of failed logins

CVEs

• CVE-2006-5052
• CVE-2007-3102

References

• http://www.redhat.com/security/updates/classification/#moderate