CVE-2020-8622

A truncated TSIG response can lead to an assertion failure

Published Aug 21, 2020 CVSS 3.1 · 6.5 Medium EPSS 5.9% KEV · Not listed
Description
In BIND 9.0.0 -> 9.11.21, 9.12.0 -> 9.16.5, 9.17.0 -> 9.17.3, also affects 9.9.3-S1 -> 9.11.21-S1 of the BIND 9 Supported Preview Edition, An attacker on the network path for a TSIG-signed request, or operating the server receiving the TSIG-signed request, could send a truncated response to that request, triggering an assertion failure, causing the server to exit. Alternately, an off-path attacker would have to correctly guess when a TSIG-signed request was sent, along with other characteristics of the packet and message, and spoof a truncated response to trigger an assertion failure, causing the server to exit.

Remediation

Vendor Solution

Upgrade to the patched release most closely related to your current version of BIND: BIND 9.11.22 BIND 9.16.6 BIND 9.17.4 BIND Supported Preview Edition is a special feature preview branch of BIND provided to eligible ISC support customers. BIND 9.11.22-S1


Vendor Workaround

No workarounds known.

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-2355-1 bind9 security update
Debian DSA Debian DSA DSA-4752-1 bind9 security update
EUVD EUVD EUVD-2020-29470 In BIND 9.0.0 -> 9.11.21, 9.12.0 -> 9.16.5, 9.17.0 -> 9.17.3, also affects 9.9.3-S1 -> 9.11.21-S1 of the BIND 9 Supported Preview Edition, An attacker on the network path for a TSIG-signed request, or operating the server receiving the TSIG-signed request, could send a truncated response to that request, triggering an assertion failure, causing the server to exit. Alternately, an off-path attacker would have to correctly guess when a TSIG-signed request was sent, along with other characteristics of the packet and message, and spoof a truncated response to trigger an assertion failure, causing the server to exit.
Ubuntu USN Ubuntu USN USN-4468-1 Bind vulnerabilities
Ubuntu USN Ubuntu USN USN-4468-2 Bind vulnerability
History

No history.