CVE-2025-40777
CVE-2025-40777 · A possible assertion failure when 'stale-answer-client-timeout' is set to '0'
This page contains facts from public vulnerability sources. Check the original advisory before updating.
If a `named` caching resolver is configured with `serve-stale-enable` `yes`, and with `stale-answer-client-timeout` set to `0` (the only allowable value other than `disabled`), and if the resolver, in the process of resolving a query, encounters a CNAME chain involving a specific combination of cached or authoritative records, the daemon will abort with an assertion failure. This issue affects BIND 9 versions 9.20.0 through 9.20.10, 9.21.0 through 9.21.9, and 9.20.9-S1 through 9.20.10-S1.
CVSS 7.5 · High · EPSS 1.0% · Fix available
- Published
- Updated
Stack: system
Affected products and versions
bind 9
- Versions
- ≥ 9.20.0, ≤ 9.20.10: Affected (custom)
- ≥ 9.21.0, ≤ 9.21.9: Affected (custom)
- ≥ 9.20.9-S1, ≤ 9.20.10-S1: Affected (custom)
- ≥ 9.18.0, ≤ 9.18.37: Not affected (custom)
- ≥ 9.18.11-S1, ≤ 9.18.37-S1: Not affected (custom)
No fix published
bind9 Debian:13
- Affected ranges
- ECOSYSTEM: < 1:9.20.11-1
Update to 1:9.20.11-1
bind9 Debian:14
- Affected ranges
- ECOSYSTEM: < 1:9.20.11-1
Update to 1:9.20.11-1