Parsing large DNS messages may cause excessive CPU load
CVE: CVE-2023-4408
Component: bind9
CWE: CWE-400
Severity: Important
CVSS v3: 7.5/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Release date: 2023-01-01T00:00:00+00:00

A flaw was found in the bind package. This issue may allow a remote attacker with no specific privileges to craft a specially long DNS message leading to an excessive and uncontrolled CPU usage, the server being unavailable, and a Denial of Service.

Statement: This vulnerability in the DNS message parsing code of BIND is of important severity due to its potential to cause excessive and uncontrolled CPU usage through specially crafted DNS queries or responses. The flaw exposes both authoritative DNS servers and recursive resolvers to Denial of Service (DoS) attacks, where an attacker can exploit the high computational complexity of the parsing routine to overwhelm the server. This can lead to significant degradation of service, rendering the DNS server unresponsive and disrupting network operations.

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.
Before applying this update, make sure all previously released errata
relevant to your system have been applied.

For details on how to apply this update, refer to:

https://access.redhat.com/articles/11258
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.
Before applying this update, make sure all previously released errata relevant to your system have been applied.

For details on how to apply this update, refer to:

https://access.redhat.com/articles/11258
Before applying this update, make sure all previously released errata relevant to your system have been applied.

For details on how to apply this update, refer to:

https://access.redhat.com/articles/11258
Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.