CVEvulnerability

CVE-2020-25687

5.9 MEDIUM Published 2021-01-20 Modified 2026-06-17 Official page ↗
Status
Modified
Published
2021-01-20
Last modified
2026-06-17
Assigner
[email protected]
CVSS 3.1 ([email protected])
5.9 MEDIUM — CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS 2.0 ([email protected])
7.1 HIGH — AV:N/AC:M/Au:N/C:N/I:N/A:C
Weaknesses
CWE-122

Description

A flaw was found in dnsmasq before version 2.83. A heap-based buffer overflow was discovered in dnsmasq when DNSSEC is enabled and before it validates the received DNS entries. This flaw allows a remote attacker, who can create valid DNS replies, to cause an overflow in a heap-allocated memory. This flaw is caused by the lack of length checks in rfc1035.c:extract_name(), which could be abused to make the code execute memcpy() with a negative size in sort_rrset() and cause a crash in dnsmasq, resulting in a denial of service. The highest threat from this vulnerability is to system availability.

Affected configurations

• thekelleys dnsmasq (< 2.83) • fedoraproject fedora 32 • fedoraproject fedora 33 • debian debian linux 9.0 • debian debian linux 10.0

Related

Weakness · CWE (1)

  • CWE-122 Heap-based Buffer Overflow weakness

References