RHBA-2011:1701 - Bug Fix Advisory

Topic

An updated pam_ldap package that fixes various bugs is now available for Red Hat
Enterprise Linux 6.

Description

The pam_ldap package provides the pam_ldap.so module, which allows PAM-aware
applications to check user passwords with the help of a directory server.

This updated pam_ldap package includes fixes for the following bugs:

• All entries stored in an LDAP directory have a unique "Distinguished Name," or

DN. The top level of the LDAP directory tree is the base, referred to as the
"base DN". When the host option is not set the pam_ldap.so module uses DNS SRV
records to determine which servers to contact to perform authentication. Prior
to this update, the LDAP base "DN" option was derived from the DNS domain name,
ignoring any value that had been set for "base" in the pam_ldap.conf file. As a
consequence, ldap lookups failed. The "base" setting in the configuration file,
pam_ldap.conf, is now correctly parsed before the configuration is read from
DNS. As a result, "base" is now set to the value given in the pam_ldap.conf file
and is used as the base (starting point) to search for a user's credentials.
(BZ#735375)

• Prior to this update, pam_ldap (when called by a process which was running as

root) did not re-authenticate the user during a password change operation. As a
consequence, reuse of the old password was not prevented. This update backports
a fix to ensure that when a privileged application initiates a password change
operation, for a user whose password has expired, that the current password is
again verified, allowing client-side password-quality checking to be performed
when using LDAP accounts. (BZ#688747)

All users of pam_ldap are advised to upgrade to this updated package, which
fixes these bugs.

Solution

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

This update is available via the Red Hat Network. Details on how to
use the Red Hat Network to apply this update are available at
https://access.redhat.com/kb/docs/DOC-11259

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

Fixes

• BZ - 688747 - pam_ldap, running as root, does not authenticate a user on password expiration
• BZ - 735375 - Base option in config file ignored if host set with DNS SRV record

CVEs

(none)

References

(none)