HOME VULNERABILITIESCVE-2023-50387

HIGH

CVE-2023-50387

CWE-770Published: February 14, 2024· Updated: Jun 17, 2026

7.5

CVSS v3.1

Official Description

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.

Technical Analysis

CVE-2023-50387 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 7.5.

CVSS v3.1 Vector Breakdown

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges Req.None

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityNone

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected Vendors & Products

Fedora1 product(s)

fedora

isc1 product(s)

bind

Microsoft6 product(s)

windows server 2008windows server 2012windows server 2016windows server 2019windows server 2022windows server 2022 23h2

nic1 product(s)

knot resolver

nlnetlabs1 product(s)

unbound

powerdns1 product(s)

recursor

Red Hat1 product(s)

enterprise linux

thekelleys1 product(s)

dnsmasq

Source: NVD CPE · 17 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time

Offensive Security exploit database

GitHub PoC Search

Community PoC repositories

Rapid7 / Metasploit

Metasploit module search

Security advisories & exploits

Official NIST entry

CVE Program entry

External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

PATCHhttps://gitlab.nic.cz/knot/knot-resolver/-/releases/v5.7.1

PATCHhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-50387

PATCHhttps://www.theregister.com/2024/02/13/dnssec_vulnerability_internet/

PATCHhttps://gitlab.nic.cz/knot/knot-resolver/-/releases/v5.7.1

PATCHhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-50387

PATCHhttps://www.theregister.com/2024/02/13/dnssec_vulnerability_internet/

ADVISORYhttps://access.redhat.com/security/cve/CVE-2023-50387

ADVISORYhttps://docs.powerdns.com/recursor/security-advisories/powerdns-advisory-2024-01.html

ADVISORYhttps://kb.isc.org/docs/cve-2023-50387

ADVISORYhttps://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2024q1/017430.html

ADVISORYhttps://news.ycombinator.com/item?id=39367411

ADVISORYhttps://nlnetlabs.nl/news/2024/Feb/13/unbound-1.19.1-released/

ADVISORYhttps://www.athene-center.de/aktuelles/key-trap

ADVISORYhttps://www.athene-center.de/fileadmin/content/PDF/Technical_Report_KeyTrap.pdf

ADVISORYhttps://www.isc.org/blogs/2024-bind-security-release/

ADVISORYhttps://www.securityweek.com/keytrap-dns-attack-could-disable-large-parts-of-internet-researchers/

ADVISORYhttps://access.redhat.com/security/cve/CVE-2023-50387

ADVISORYhttps://docs.powerdns.com/recursor/security-advisories/powerdns-advisory-2024-01.html

ADVISORYhttps://kb.isc.org/docs/cve-2023-50387

ADVISORYhttps://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2024q1/017430.html

ADVISORYhttps://news.ycombinator.com/item?id=39367411

ADVISORYhttps://nlnetlabs.nl/news/2024/Feb/13/unbound-1.19.1-released/

ADVISORYhttps://www.athene-center.de/aktuelles/key-trap

ADVISORYhttps://www.athene-center.de/fileadmin/content/PDF/Technical_Report_KeyTrap.pdf

ADVISORYhttps://www.isc.org/blogs/2024-bind-security-release/

ADVISORYhttps://www.securityweek.com/keytrap-dns-attack-could-disable-large-parts-of-internet-researchers/

All References (66)

→

http://www.openwall.com/lists/oss-security/2024/02/16/2Mailing List

→

http://www.openwall.com/lists/oss-security/2024/02/16/3Mailing List

→

https://access.redhat.com/security/cve/CVE-2023-50387Third Party Advisory

→

https://bugzilla.suse.com/show_bug.cgi?id=1219823Issue Tracking

→

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

→

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

→

https://kb.isc.org/docs/cve-2023-50387Third Party Advisory · VDB Entry

→

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

→

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

→

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6FV5O347JTX7P5OZA6NGO4MKTXRXMKOZ/

→

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BUIP7T7Z4T3UHLXFWG6XIVDP4GYPD3AI/Mailing List

→

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HVRDSJVZKMCXKKPP6PNR62T7RWZ3YSDZ/

→

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IGSLGKUAQTW5JPPZCMF5YPEYALLRUZZ6/

→

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PNNHZSZPG2E7NBMBNYPGHCFI4V4XRWNQ/Mailing List

→

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RGS7JN6FZXUSTC2XKQHH27574XOULYYJ/

Quick Facts

CVE IDCVE-2023-50387

CVSS Score7.5 / 10

SeverityHIGH

WeaknessCWE-770

CISA KEVNo

Affected8 vendor(s)

PublishedFeb 14, 2024

Related CVEs (CWE-770)

Recommended Actions

→Apply vendor patches immediately
→Monitor CVE-2023-50387 in threat intel feeds
→Review IDS/IPS signatures for exploitation attempts

Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.

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