CVE-2023-50387

HIGHCVSS 7.5/10EPSS 100.00%

Last modified

CVE-2023-50387 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. 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.. EPSS estimates a 100.00% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1
7.5/10

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

EPSS Probability
100.00%

100.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersionsUpdate
RedhatEnterprise Linux6.0
RedhatEnterprise Linux7.0
RedhatEnterprise Linux8.0
RedhatEnterprise Linux9.0
MicrosoftWindows Server 2008r2Sp1
MicrosoftWindows Server 2012All versions
MicrosoftWindows Server 2012r2
MicrosoftWindows Server 2016All versions
MicrosoftWindows Server 2019All versions
MicrosoftWindows Server 2022All versions
MicrosoftWindows Server 2022 23h2All versions
FedoraprojectFedora39
ThekelleysDnsmasq< 2.90
NicKnot Resolver< 5.71
PowerdnsRecursor>= 4.8.0, < 4.8.6
PowerdnsRecursor>= 4.9.0, < 4.9.3
PowerdnsRecursor>= 5.0.0, < 5.0.2
IscBind>= 9.0.0, <= 9.16.46
IscBind>= 9.18.0, <= 9.18.22
IscBind>= 9.19.0, <= 9.19.20
NlnetlabsUnbound< 1.19.1

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2023-50387?
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.
How severe is CVE-2023-50387?
CVE-2023-50387 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 100.00% probability of exploitation in the next 30 days.
How do I fix CVE-2023-50387?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2023-50387?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST