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CVE-2023-50868

Exploitation: none CVSS 7.5 HIGH

CVSS base score: 7.5 (High) CISA · v3.1

Score assigned by CISA's Vulnrichment program; the vendor's CVE record did not include one.

Vendor: n/a   Product: n/a

Description

The Closest Encloser Proof aspect of the DNS protocol (in RFC 5155 when RFC 9276 guidance is skipped) allows remote attackers to cause a denial of service (CPU consumption for SHA-1 computations) via DNSSEC responses in a random subdomain attack, aka the "NSEC3" issue. The RFC 5155 specification implies that an algorithm must perform thousands of iterations of a hash function in certain situations.

Lifecycle Timeline

Each milestone comes from a different source, so gaps between them are gaps in what those sources publish, not evidence that nothing happened. EPSS history for this CVE holds 148 points from 2024-02-17, tracked daily from 2026-09-09; earlier points are weekly, which dates a spike to within a week. Peak probability 82.8% on 2026-06-20.

Published Applicability

Red Hat CSAF/VEX 0 affected · 4008 fixed · 115 not affected
OSV.dev (incl. GHSA) 13 affected · 9 fixed · 0 not affected
CVE List v5 (CNA container) 1 affected · 0 fixed · 0 not affected

Check whether a specific version is affected →

What each source publishes about which product versions carry this vulnerability, kept as written rather than merged. Absence here means no source has published applicability data, not that nothing is affected.

Research & News Coverage

No mentions found in monitored research blogs or news feeds.

Detection & Exploitation

Exploit / Pen Test
Network IDS/IPS
none published
Host / SIEM
none published

Coverage across public collections only: Nuclei and OpenVAS NVT (scan); Snort and Suricata ET Open (network); Sigma and YARA (host/SIEM); Metasploit, Exploit-DB and public GitHub repositories (exploit). Absence here means nothing public was found, not that detection is impossible.
GitHub PoC repositories are collected automatically by PoC-in-GitHub (CC0) and are not vetted: some are fakes and some are malware. Treat them as evidence that code was published, not as code to run.
OpenVAS coverage derives from the Greenbone Community Feed, made available under the Open Database License (ODbL) v1.0; its individual Vulnerability Tests are licensed GNU GPL v2.

Distribution Status

Debian · bind9 bookworm 1:9.18.24-1 trixie 1:9.19.21-1 forky 1:9.19.21-1 sid 1:9.19.21-1 scope: local
Debian · dnsjava bookworm trixie 3.6.2-1 forky 3.6.2-1 sid 3.6.2-1 scope: local
Debian · dnsmasq bookworm 2.90-4~deb12u1 trixie 2.90-1 forky 2.90-1 sid 2.90-1 scope: local
Debian · knot-resolver bookworm 5.6.0-1+deb12u1 trixie 5.7.1-1 forky 5.7.1-1 sid 5.7.1-1 scope: local
Debian · pdns-recursor bookworm 4.8.6-1 trixie 4.9.3-1 forky 4.9.3-1 sid 4.9.3-1 scope: local
Debian · systemd bookworm 252.23-1~deb12u1 trixie 255.4-1 forky 255.4-1 sid 255.4-1 scope: local
Debian · unbound bookworm 1.17.1-2+deb12u2 trixie 1.19.1-1 forky 1.19.1-1 sid 1.19.1-1 scope: local

Where the distribution has shipped a fix, and in which version. Green means the release has resolved it, amber that it is still open. Data from the Debian Security Tracker, used under Debian's MIT / GPLv2+ terms. Debian is upstream of several other distributions, so a fix here often precedes theirs.

CISA Assessment (Vulnrichment / SSVC)

none
yes
partial
7.5 HIGH
—
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
CWE-400 — Uncontrolled Resource Consumption
2025-05-12

Listed By

SourceDateRecord
CISA Vulnrichment 2025-05-12 source record →

Referenced in Advisories

DateAdvisoryIssuer
2024-02-13 ISC Releases Security Advisories for BIND 9 CISA

Weaponization Timeline — Offensive & Testing Tools

No exploit-tool sightings recorded for this CVE.

Evidence tiers are explained on the About page — a merged Metasploit module is far stronger evidence than a distro package mention.

External References