An attacker who is able to send and receive messages to an authoritative DNS server and who has knowledge of a valid TSIG key name for the zone and service being targeted may be able to manipulate BIND into accepting an unauthorized dynamic update. A server that relies solely on TSIG or SIG(0) keys with no other address-based ACL protection could be vulnerable to malicious zone content manipulation using this technique.

Workarounds:

The effects of this vulnerability can be mitigated by using Access Control Lists (ACLs) that require both address range validation and use of TSIG authentication in parallel. For information on how to configure this type of compound authentication control, please see:

https://kb.isc.org/article/AA-00723/0/Using-Access-Control-Lists-ACLs-with-both-addresses-and-keys.html.

Administrators who have made use of named.conf option "update-policy local;" should refer to the Administrator Reference Manual (ARM) for details of the automatic update policy that will be established and to assess whether or not this conveys any additional risk to their server. (Note that this option is not enabled by default).

Upstream patch:

https://source.isc.org/cgi-bin/gitweb.cgi?p=bind9.git;a=commitdiff;h=581c1526ab