==========================================================================
Ubuntu Security Notice USN-6642-1
February 19, 2024

bind9 vulnerabilities
==========================================================================

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 20.04 LTS

Summary:

Several security issues were fixed in Bind.

Software Description:
- bind9: Internet Domain Name Server

Details:

Shoham Danino, Anat Bremler-Barr, Yehuda Afek, and Yuval Shavitt discovered
that Bind incorrectly handled parsing large DNS messages. A remote attacker
could possibly use this issue to cause Bind to consume resources, leading
to a denial of service. (CVE-2023-4408)

Elias Heftrig, Haya Schulmann, Niklas Vogel, and Michael Waidner discovered
that Bind icorrectly handled validating DNSSEC messages. A remote attacker
could possibly use this issue to cause Bind to consume resources, leading
to a denial of service. (CVE-2023-50387)

It was discovered that Bind incorrectly handled preparing an NSEC3 closest
encloser proof. A remote attacker could possibly use this issue to cause
Bind to consume resources, leading to a denial of service. (CVE-2023-50868)

It was discovered that Bind incorrectly handled reverse zone queries when
nxdomain-redirect is enabled. A remote attacker could possibly use this
issue to cause Bind to crash, leading to a denial of service.
(CVE-2023-5517)

It was discovered that Bind incorrectly handled certain specific recursive
query patterns. A remote attacker could possibly use this issue to cause
Bind to consume memory, leading to a denial of service. (CVE-2023-6516)

Bind has been updated to 9.6.48. In addition to security fixes, the updated
packages contain bug fixes, new features, and possibly incompatible
changes.

Please see the following for more information:
https://downloads.isc.org/isc/bind9/9.16.48/doc/arm/html/notes.html

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 20.04 LTS:
   bind9                           1:9.16.48-0ubuntu0.20.04.1

This update uses a new upstream release, which includes additional bug
fixes. In general, a standard system update will make all the necessary
changes.

References:
   https://ubuntu.com/security/notices/USN-6642-1
   CVE-2023-4408, CVE-2023-50387, CVE-2023-50868, CVE-2023-5517,
   CVE-2023-6516

Package Information:
   https://launchpad.net/ubuntu/+source/bind9/1:9.16.48-0ubuntu0.20.04.1