CVE-2020-25681

Name: CVE-2020-25681
Creator: NVD / NIST
Published: 2021-01-20T17:15:12.843+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.1/10EPSS 81.32%

Last modified Jun 17, 2026

CVE-2020-25681 is a high-severity vulnerability rated 8.1/10 on the CVSS scale. A flaw was found in dnsmasq before version 2.83. A heap-based buffer overflow was discovered in the way RRSets are sorted before validating with DNSSEC data. EPSS estimates a 81.32% chance of exploitation in the next 30 days.

Description

A flaw was found in dnsmasq before version 2.83. A heap-based buffer overflow was discovered in the way RRSets are sorted before validating with DNSSEC data. An attacker on the network, who can forge DNS replies such as that they are accepted as valid, could use this flaw to cause a buffer overflow with arbitrary data in a heap memory segment, possibly executing code on the machine. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

Metrics

CVSS 3.1

8.1/10

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

EPSS Probability

81.32%

99.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-122

Affected Software

Vendor	Product	Versions
Thekelleys	Dnsmasq	< 2.83
Fedoraproject	Fedora	32
Fedoraproject	Fedora	33
Debian	Debian Linux	9.0
Debian	Debian Linux	10.0

References

https://bugzilla.redhat.com/show_bug.cgi?id=1881875Issue Tracking, Patch, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2021/03/msg00027.htmlMailing List, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QGB7HL3OWHTLEPSMLDGOMXQKG3KM2QME/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WYW3IR6APUSKOYKL5FT3ACTIHWHGQY32/
https://security.gentoo.org/glsa/202101-17Third Party Advisory
https://www.debian.org/security/2021/dsa-4844Third Party Advisory
https://www.jsof-tech.com/disclosures/dnspooq/Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1881875Issue Tracking, Patch, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2021/03/msg00027.htmlMailing List, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QGB7HL3OWHTLEPSMLDGOMXQKG3KM2QME/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WYW3IR6APUSKOYKL5FT3ACTIHWHGQY32/
https://security.gentoo.org/glsa/202101-17Third Party Advisory
https://www.debian.org/security/2021/dsa-4844Third Party Advisory
https://www.jsof-tech.com/disclosures/dnspooq/Third Party Advisory
https://www.kb.cert.org/vuls/id/434904

Timeline

Published: Jan 20, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-25681?

How severe is CVE-2020-25681?

CVE-2020-25681 has a CVSS score of 8.1/10 (HIGH severity). The EPSS model estimates a 81.32% probability of exploitation in the next 30 days.

How do I fix CVE-2020-25681?

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-2020-25681?

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

Scan your code now

Source: NVD / NIST