-----BEGIN PGP SIGNED MESSAGE-----
AUSCERT External Security Bulletin Redistribution
ESB-2008.0546 -- [RedHat]
Low: nss_ldap security and bug fix update
26 May 2008
AusCERT Security Bulletin Summary
Publisher: Red Hat
Operating System: Red Hat Linux 5
Impact: Access Privileged Data
CVE Names: CVE-2007-5794
Original Bulletin: https://rhn.redhat.com/errata/RHSA-2008-0389.html
- --------------------------BEGIN INCLUDED TEXT--------------------
- -----BEGIN PGP SIGNED MESSAGE-----
Red Hat Security Advisory
Synopsis: Low: nss_ldap security and bug fix update
Advisory ID: RHSA-2008:0389-02
Product: Red Hat Enterprise Linux
Advisory URL: https://rhn.redhat.com/errata/RHSA-2008-0389.html
Issue date: 2008-05-20
Updated on: 2008-05-21
Keywords: dns thread port rebuild exop referral
CVE Names: CVE-2007-5794
An updated nss_ldap package that fixes a security issue and several bugs is
This update has been rated as having low security impact by the Red Hat
Security Response Team.
2. Relevant releases/architectures:
Red Hat Enterprise Linux Desktop (v. 5 client) - i386, x86_64
Red Hat Enterprise Linux (v. 5 server) - i386, ia64, ppc, s390x, x86_64
The nss_ldap package contains the nss_ldap and pam_ldap modules. The
nss_ldap module is a plug-in which allows applications to retrieve
information about users and groups from a directory server. The pam_ldap
module allows PAM-aware applications to use a directory server to verify
A race condition was discovered in nss_ldap which affected certain
applications which make LDAP connections, such as Dovecot. This could cause
nss_ldap to answer a request for information about one user with
information about a different user. (CVE-2007-5794)
In addition, these updated packages fix the following bugs:
* a build error prevented the nss_ldap module from being able to use DNS to
discover the location of a directory server. For example, when the
/etc/nsswitch.conf configuration file was configured to use "ldap", but no
"host" or "uri" option was configured in the /etc/ldap.conf configuration
file, no directory server was contacted, and no results were returned.
* the "port" option in the /etc/ldap.conf configuration file on client
machines was ignored. For example, if a directory server which you were
attempting to use was listening on a non-default port (i.e. not ports 389
or 636), it was only possible to use that directory server by including the
port number in the "uri" option. In this updated package, the "port" option
works as expected.
* pam_ldap failed to change an expired password if it had to follow a
referral to do so, which could occur, for example, when using a slave
directory server in a replicated environment. An error such as the
following occurred after entering a new password: "LDAP password
information update failed: Can't contact LDAP server Insufficient 'write'
privilege to the 'userPassword' attribute"
This has been resolved in this updated package.
* when the "pam_password exop_send_old" password-change method was
configured in the /etc/ldap.conf configuration file, a logic error in the
pam_ldap module caused client machines to attempt to change a user's
password twice. First, the pam_ldap module attempted to change the password
using the "exop" request, and then again using an LDAP modify request.
* on Red Hat Enterprise Linux 5.1, rebuilding nss_ldap-253-5.el5 when the
krb5-*-1.6.1-17.el5 packages were installed failed due to an error such as
+ /builddir/build/SOURCES/dlopen.sh ./nss_ldap-253/nss_ldap.so
dlopen() of "././nss_ldap-253/nss_ldap.so" failed:
./././nss_ldap-253/nss_ldap.so: undefined symbol: request_key
error: Bad exit status from /var/tmp/rpm-tmp.62652 (%build)
The missing libraries have been added, which resolves this issue.
When recursively enumerating the set of members in a given group, the
module would allocate insufficient space for storing the set of member
names if the group itself contained other groups, thus corrupting the heap.
This update includes a backported fix for this bug.
Users of nss_ldap should upgrade to these updated packages, which contain
backported patches to correct this issue and fix these bugs.
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
5. Bugs fixed (http://bugzilla.redhat.com/):
254172 - Automatic DNS discovery of the LDAP server does not work
364501 - pam_ldap tries to change passwords twice
367461 - CVE-2007-5794 nss_ldap randomly replying with wrong user's data
427370 - RHEL 5.1 nss_ldap does not build with RHEL 5.1 krb5 packages
6. Package List:
Red Hat Enterprise Linux Desktop (v. 5 client):
Red Hat Enterprise Linux (v. 5 server):
These packages are GPG signed by Red Hat for security. Our key and
details on how to verify the signature are available from
The Red Hat security contact is <firstname.lastname@example.org>. More contact
details at https://www.redhat.com/security/team/contact/
Copyright 2008 Red Hat, Inc.
- -----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.4 (GNU/Linux)
- -----END PGP SIGNATURE-----
- --------------------------END INCLUDED TEXT--------------------
You have received this e-mail bulletin as a result of your organisation's
registration with AusCERT. The mailing list you are subscribed to is
maintained within your organisation, so if you do not wish to continue
receiving these bulletins you should contact your local IT manager. If
you do not know who that is, please send an email to email@example.com
and we will forward your request to the appropriate person.
NOTE: Third Party Rights
This security bulletin is provided as a service to AusCERT's members. As
AusCERT did not write the document quoted above, AusCERT has had no control
over its content. The decision to follow or act on information or advice
contained in this security bulletin is the responsibility of each user or
organisation, and should be considered in accordance with your organisation's
site policies and procedures. AusCERT takes no responsibility for consequences
which may arise from following or acting on information or advice contained in
this security bulletin.
NOTE: This is only the original release of the security bulletin. It may
not be updated when updates to the original are made. If downloading at
a later date, it is recommended that the bulletin is retrieved directly
from the author's website to ensure that the information is still current.
Contact information for the authors of the original document is included
in the Security Bulletin above. If you have any questions or need further
information, please contact them directly.
Previous advisories and external security bulletins can be retrieved from:
If you believe that your computer system has been compromised or attacked in
any way, we encourage you to let us know by completing the secure National IT
Incident Reporting Form at:
Australian Computer Emergency Response Team
The University of Queensland
Internet Email: firstname.lastname@example.org
Facsimile: (07) 3365 7031
Telephone: (07) 3365 4417 (International: +61 7 3365 4417)
AusCERT personnel answer during Queensland business hours
which are GMT+10:00 (AEST).
On call after hours for member emergencies only.
-----BEGIN PGP SIGNATURE-----
-----END PGP SIGNATURE-----