CVE-2020-25681

dnsmasq: heap-based buffer overflow in sort_rrset() when DNSSEC is enabled

Published Jan 20, 2021 CVSS 3.1 · 8.1 High EPSS 84.1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-2604-1 dnsmasq security update
Debian DSA Debian DSA DSA-4844-1 dnsmasq security update
Ubuntu USN Ubuntu USN USN-4698-1 Dnsmasq vulnerabilities
Weaknesses

Sources

Status
PUBLISHED
Assigner
redhat
Published
Updated
Nov 4, 2025, 7:12 PM
Reserved
Sep 16, 2020, 12:00 AM
Status
Modified
Published
Jan 20, 2021, 5:15 PM
Modified
Jun 17, 2026, 3:07 AM
Severity
Important
Public date
Jan 19, 2021, 12:00 AM