A flaw was found in dnsmasq before 2.83. A buffer overflow vulnerability was discovered in the way dnsmasq extract names from DNS packets before validating them with DNSSEC data. An attacker on the network, who can create valid DNS replies, could use this flaw to cause an overflow with arbitrary data in a heap-allocated memory, possibly executing code on the machine. The flaw is in the rfc1035.c:extract_name() function, which writes data to the memory pointed by name assuming MAXDNAME*2 bytes are available in the buffer. However, in some code execution paths, it is possible extract_name() gets passed an offset from the base buffer, thus reducing, in practice, the number of available bytes that can be written in the buffer. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
History

No history.

cve-icon MITRE

Status: PUBLISHED

Assigner: redhat

Published: 2021-01-20T16:28:38

Updated: 2024-08-04T15:40:36.918Z

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

Link: CVE-2020-25682

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Modified

Published: 2021-01-20T17:15:12.920

Modified: 2024-11-21T05:18:27.207

Link: CVE-2020-25682

cve-icon Redhat

Severity : Important

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

Links: CVE-2020-25682 - Bugzilla