CVE-2020-19861

Name: CVE-2020-19861
Creator: NVD / NIST
Published: 2022-01-21T15:15:07.607+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 1.49%

Last modified Jun 17, 2026

CVE-2020-19861 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. When a zone file in ldns 1.7.1 is parsed, the function ldns_nsec3_salt_data is too trusted for the length value obtained from the zone file. When the memcpy is copied, the 0xfe - ldns_rdf_size(salt_rdf) byte data can be copied, causing heap overflow information leakage.. EPSS estimates a 1.49% chance of exploitation in the next 30 days.

Description

When a zone file in ldns 1.7.1 is parsed, the function ldns_nsec3_salt_data is too trusted for the length value obtained from the zone file. When the memcpy is copied, the 0xfe - ldns_rdf_size(salt_rdf) byte data can be copied, causing heap overflow information leakage.

Metrics

CVSS 3.1

7.5/10

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

EPSS Probability

1.49%

70.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-125

Affected Software

Vendor	Product	Versions
Nlnetlabs	Ldns	1.7.1

References

https://cwe.mitre.org/data/definitions/126.htmlThird Party Advisory
https://github.com/NLnetLabs/ldns/issues/51Exploit, Issue Tracking, Third Party Advisory
https://cwe.mitre.org/data/definitions/126.htmlThird Party Advisory
https://github.com/NLnetLabs/ldns/issues/51Exploit, Issue Tracking, Third Party Advisory

Timeline

Published: Jan 21, 2022
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-19861?

How severe is CVE-2020-19861?

CVE-2020-19861 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 1.49% probability of exploitation in the next 30 days.

How do I fix CVE-2020-19861?

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-2020-19861?

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

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Source: NVD / NIST