CVE-2023-50868

high-risk

Published 2024-02-14

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.

Do I need to act?

11.8% chance of exploitation in next 30 days

EPSS score — higher than 88% of all CVEs

Not on CISA KEV list

No confirmed active exploitation reported to CISA

Patch status unknown

Check vendor advisories for fix availability and mitigation guidance

CVSS 7.5/10 High

NETWORK / LOW complexity

Affected Products (16)

Bind

Fedora

Debian Linux

Enterprise Linux

Recursor

Bootstrap Os

Active Iq Unified Manager

Hci Baseboard Management Controller

Affected Vendors

Debian Redhat Isc Powerdns Fedoraproject Netapp

References (53)

Issue Tracking http://www.openwall.com/lists/oss-security/2024/02/16/2

Issue Tracking http://www.openwall.com/lists/oss-security/2024/02/16/3

Vendor Advisory https://access.redhat.com/security/cve/CVE-2023-50868

Issue Tracking https://bugzilla.suse.com/show_bug.cgi?id=1219826

Technical Description https://datatracker.ietf.org/doc/html/rfc5155

Vendor Advisory https://docs.powerdns.com/recursor/security-advisories/powerdns-advisory-2024-01...

Release Notes https://gitlab.nic.cz/knot/knot-resolver/-/releases/v5.7.1

Third Party Advisory https://kb.isc.org/docs/cve-2023-50868

Vendor Advisory https://lists.debian.org/debian-lts-announce/2024/02/msg00006.html

Vendor Advisory https://lists.debian.org/debian-lts-announce/2024/05/msg00011.html

Vendor Advisory https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro...

and 33 more references

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high-risk

Severity 26/34 · High

Exploitability 11/34 · Low

Exposure 18/34 · Moderate