A logic error in code which checks TSIG validity can be used to trigger an assertion failure in tsig.c
CVE: CVE-2020-8617
Component: bind
CWE: CWE-617
Severity: Important
CVSS v3: 7.5/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Release date: 2020-05-19T00:00:00+00:00

An assertion failure was found in BIND, which checks the validity of messages containing TSIG resource records. This flaw allows an attacker that knows or successfully guesses the name of the TSIG key used by the server to use a specially-crafted message, potentially causing a BIND server to reach an inconsistent state or cause a denial of service. A majority of BIND servers have an internally-generated TSIG session key whose name is trivially guessable, and that key exposes the vulnerability unless specifically disabled.

Statement: Upstream has released additional information about this flaw. Details available at: https://kb.isc.org/docs/cve-2020-8617-faq-and-supplemental-information

Remediation:
For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

After installing the update, the BIND daemon (named) will be restarted automatically.
For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

After installing the update, the BIND daemon (named) will be restarted automatically.
For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

After installing the update, the BIND daemon (named) will be restarted automatically.
For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

After installing the update, the BIND daemon (named) will be restarted automatically.
For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

After installing the update, the BIND daemon (named) will be restarted automatically.
For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

After installing the update, the BIND daemon (named) will be restarted automatically.
For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

After installing the update, the BIND daemon (named) will be restarted automatically.
For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

After installing the update, the BIND daemon (named) will be restarted automatically.
For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

After installing the update, the BIND daemon (named) will be restarted automatically.
For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

After installing the update, the BIND daemon (named) will be restarted automatically.
For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

After installing the update, the BIND daemon (named) will be restarted automatically.
For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

After installing the update, the BIND daemon (named) will be restarted automatically.
BIND servers have an internally-generated TSIG session key whose name is trivially guessable, and that key exposes the vulnerability unless specifically disabled. Upstream recommends using random value in session-keyname as a workaround. This can be added to named.conf configuration file.