CVE-2020-25681: debian debian_linux Heap-based Buffer Overflow

Vulnerability summary

CVE-2020-25681 is a high (CVSS 8.3) Heap-based Buffer Overflow vulnerability in debian debian_linux. EPSS estimates a 81.19% chance of exploitation in the next 30 days, higher than 99.6% of scored vulnerabilities.

Timeline

1. 20-01-2021
   PublishedVulnerability first disclosed.
2. 04-11-2025
   Last modifiedVulnerability information updated.

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.

• CWE-122Heap-based Buffer OverflowA heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().