CVE-2023-2828
bind9 - security update
Description
Every `named` instance configured to run as a recursive resolver maintains a cache database holding the responses to the queries it has recently sent to authoritative servers. The size limit for that cache database can be configured using the `max-cache-size` statement in the configuration file; it defaults to 90% of the total amount of memory available on the host. When the size of the cache reaches 7/8 of the configured limit, a cache-cleaning algorithm starts to remove expired and/or least-recently used RRsets from the cache, to keep memory use below the configured limit. It has been discovered that the effectiveness of the cache-cleaning algorithm used in `named` can be severely diminished by querying the resolver for specific RRsets in a certain order, effectively allowing the configured `max-cache-size` limit to be significantly exceeded. This issue affects BIND 9 versions 9.11.0 through 9.16.41, 9.18.0 through 9.18.15, 9.19.0 through 9.19.13, 9.11.3-S1 through 9.16.41-S1, and 9.18.11-S1 through 9.18.15-S1.
How to fix CVE-2023-2828
To remediate CVE-2023-2828, upgrade the affected package to a fixed version below.
- —upgrade to 1:9.16.42-1~deb11u1 or later
- —upgrade to 1:9.11.5.P4+dfsg-5.1+deb10u9 or later
- —upgrade to 1:9.16.42-1~deb11u1 or later
Is CVE-2023-2828 being exploited?
Low — EPSS is 0.9%, meaning exploitation activity has not been observed at scale.
Affected packages (3)
- from 0, < 1:9.16.42-1~deb11u1
- from 0, < 1:9.11.5.P4+dfsg-5.1+deb10u9
- from 0, < 1:9.16.42-1~deb11u1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |