CVE-2023-50387
HIGH 7.5EPSS 100.0%
Certain DNSSEC aspects of the DNS protocol (in RFC 4033, 4034, 4035, 6840, and related RFCs) allow remote attackers to cause a denial of service (CPU consumption) via one or more DNSSEC responses, aka the "KeyTrap" issue. One of the concerns is that, when there is a zone with many DNSKEY and RRSIG records, the protocol specification implies that an algorithm must evaluate all combinations of DNSKEY and RRSIG records.
- CVSS v3.1 NVD
- 7.5 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - EPSS
- 99.99% chance of exploitation in the next 30 days, 100th percentile
- Published
- 2024-02-14
- Updated
- 2025-11-04
Proof-of-concept exploits (5)
- Meirelez/SSR-DNSSEC0★ · 2024-05-23
- Pablodiz/CVE-2023-503870★ · 2024-12-05
- knqyf263/CVE-2023-5038744★ · 2024-02-18
- sub148/vuln-triage0★ · 2026-09-02
- 666564657269636f/DNSSec0★ · 2026-09-02
Security advisories
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-50387
- https://nlnetlabs.nl/news/2024/Feb/13/unbound-1.19.1-released
- https://access.redhat.com/security/cve/CVE-2023-50387
- https://docs.powerdns.com/recursor/security-advisories/powerdns-advisory-2024-01.html
- https://kb.isc.org/docs/cve-2023-50387
- https://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2024q1/017430.html
- https://news.ycombinator.com/item?id=39367411
- https://www.athene-center.de/aktuelles/key-trap
- https://www.athene-center.de/fileadmin/content/PDF/Technical_Report_KeyTrap.pdf
- https://www.isc.org/blogs/2024-bind-security-release
- https://www.securityweek.com/keytrap-dns-attack-could-disable-large-parts-of-internet-res…
- https://www.theregister.com/2024/02/13/dnssec_vulnerability_internet
- https://gitlab.nic.cz/knot/knot-resolver/-/releases/v5.7.1
- https://bugzilla.suse.com/show_bug.cgi?id=1219823
- https://news.ycombinator.com/item?id=39372384