Synopsis:	Low: nss_ldap security and bug fix update
Issue date:	2008-05-21
CVE Names:	CVE-2007-5794

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
the following:

        + /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.

SL 5.x

    SRPMS:
nss_ldap-253-12.el5.src.rpm
    i386:
nss_ldap-253-12.el5.i386.rpm
    x86_64:
nss_ldap-253-12.el5.i386.rpm
nss_ldap-253-12.el5.x86_64.rpm

-Connie Sieh
-Troy Dawson