The handle_connection_error function in ldap_helper.c in bind-dyndb-ldap before 1.1.0rc1 does not properly handle LDAP query errors, which allows remote attackers to cause a denial of service (infinite loop and named server hang) via a non-alphabet character in the base DN in an LDAP search DNS query.

From Red Hat Security Advisory 2012:0683 :

An updated bind-dyndb-ldap package that fixes one security issue is now available for Red Hat Enterprise Linux 6.

The Red Hat Security Response Team has rated this update as having important security impact. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available from the CVE link in the References section.

The dynamic LDAP back end is a plug-in for BIND that provides back-end capabilities to LDAP databases. It features support for dynamic updates and internal caching that help to reduce the load on LDAP servers.

A flaw was found in the way bind-dyndb-ldap handled LDAP query errors.
If a remote attacker were able to send DNS queries to a named server that is configured to use bind-dyndb-ldap, they could trigger such an error with a DNS query leveraging bind-dyndb-ldap's insufficient escaping of the LDAP base DN (distinguished name). This would result in an invalid LDAP query that named would retry in a loop, preventing it from responding to other DNS queries. With this update, bind-dyndb-ldap only attempts to retry one time when an LDAP search returns an unexpected error. (CVE-2012-2134)

Red Hat would like to thank Ronald van Zantvoort for reporting this issue.

All bind-dyndb-ldap users should upgrade to this updated package, which contains a backported patch to correct this issue. For the update to take effect, the named service must be restarted.

The dynamic LDAP back end is a plug-in for BIND that provides back-end capabilities to LDAP databases. It features support for dynamic updates and internal caching that help to reduce the load on LDAP servers.

A flaw was found in the way bind-dyndb-ldap handled LDAP query errors.
If a remote attacker were able to send DNS queries to a named server that is configured to use bind-dyndb-ldap, they could trigger such an error with a DNS query leveraging bind-dyndb-ldap's insufficient escaping of the LDAP base DN (distinguished name). This would result in an invalid LDAP query that named would retry in a loop, preventing it from responding to other DNS queries. With this update, bind-dyndb-ldap only attempts to retry one time when an LDAP search returns an unexpected error. (CVE-2012-2134)

All bind-dyndb-ldap users should upgrade to this updated package, which contains a backported patch to correct this issue. For the update to take effect, the named service must be restarted.

Update to the 1.1.0rc1 version which fixes CVE-2012-2134.

  - it was possible to DoS named process by query which     contained non-alphabet characters and which belongs to     zone served by the plugin. (CVE-2012-2134)

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

An updated bind-dyndb-ldap package that fixes one security issue is now available for Red Hat Enterprise Linux 6.

The Red Hat Security Response Team has rated this update as having important security impact. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available from the CVE link in the References section.

The dynamic LDAP back end is a plug-in for BIND that provides back-end capabilities to LDAP databases. It features support for dynamic updates and internal caching that help to reduce the load on LDAP servers.

A flaw was found in the way bind-dyndb-ldap handled LDAP query errors.
If a remote attacker were able to send DNS queries to a named server that is configured to use bind-dyndb-ldap, they could trigger such an error with a DNS query leveraging bind-dyndb-ldap's insufficient escaping of the LDAP base DN (distinguished name). This would result in an invalid LDAP query that named would retry in a loop, preventing it from responding to other DNS queries. With this update, bind-dyndb-ldap only attempts to retry one time when an LDAP search returns an unexpected error. (CVE-2012-2134)

Red Hat would like to thank Ronald van Zantvoort for reporting this issue.

All bind-dyndb-ldap users should upgrade to this updated package, which contains a backported patch to correct this issue. For the update to take effect, the named service must be restarted.

ID	Name	Product	Family	Severity
68530	Oracle Linux 6 : bind-dyndb-ldap (ELSA-2012-0683)	Nessus	Oracle Linux Local Security Checks	medium
61314	Scientific Linux Security Update : bind-dyndb-ldap on SL6.x i386/x86_64 (20120521)	Nessus	Scientific Linux Local Security Checks	medium
59259	Fedora 17 : bind-dyndb-ldap-1.1.0-0.11.rc1.fc17 (2012-6666)	Nessus	Fedora Local Security Checks	medium
59233	CentOS 6 : bind-dyndb-ldap (CESA-2012:0683)	Nessus	CentOS Local Security Checks	medium
59224	RHEL 6 : bind-dyndb-ldap (RHSA-2012:0683)	Nessus	Red Hat Local Security Checks	medium
59100	Fedora 15 : bind-dyndb-ldap-1.1.0-0.11.rc1.fc15 (2012-6759)	Nessus	Fedora Local Security Checks	medium
59099	Fedora 16 : bind-dyndb-ldap-1.1.0-0.11.rc1.fc16 (2012-6722)	Nessus	Fedora Local Security Checks	medium

Detections

Analytics

CVE-2012-2134

high

Tenable Plugins

medium

medium

medium

medium

medium

medium

medium