Processing of repeated responses to the same query, where both responses contain ECS pseudo-options, but where the first is broken in some way, can cause BIND to exit with an assertion failure.
\'Broken\' in this context is anything that would cause the resolver to reject the query response, such as a mismatch between query and answer name.
This issue affects BIND 9 versions 9.11.4-S1 through 9.11.37-S1 and 9.16.8-S1 through 9.16.36-S1.
Metrics
CVSS Version: 3.1 |
Base Score: 7.5 HIGH Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Common Attack Pattern Enumeration and Classification (CAPEC)
CAPEC-ID: CAPEC Description: An attacker controlling a malicious nameserver could respond with two responses in quick succession, each with a "CLIENT-SUBNET" pseudo-option and where the first is broken. Processing the second response after the first causes named to terminate.
All affected versions of the BIND Supported Preview Edition are vulnerable, including those that are not configured to use ECS.