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.
History

No history.

cve-icon MITRE

Status: PUBLISHED

Assigner: redhat

Published: 2021-01-20T16:31:41

Updated: 2024-08-04T15:40:36.629Z

Reserved: 2020-09-16T00:00:00

Link: CVE-2020-25687

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Modified

Published: 2021-01-20T17:15:13.060

Modified: 2024-11-21T05:18:28.237

Link: CVE-2020-25687

cve-icon Redhat

Severity : Moderate

Publid Date: 2021-01-19T00:00:00Z

Links: CVE-2020-25687 - Bugzilla