CVE-2020-25683

medium

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. A remote attacker, who can create valid DNS replies, could use this flaw 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 get_rdata() and cause a crash in dnsmasq, resulting in a denial of service. The highest threat from this vulnerability is to system availability.

References

https://bugzilla.redhat.com/show_bug.cgi?id=1882018

https://lists.debian.org/debian-lts-announce/2021/03/msg00027.html

https://lists.fedoraproject.org/archives/list/[email protected]/message/QGB7HL3OWHTLEPSMLDGOMXQKG3KM2QME/

https://lists.fedoraproject.org/archives/list/[email protected]/message/WYW3IR6APUSKOYKL5FT3ACTIHWHGQY32/

https://security.gentoo.org/glsa/202101-17

https://www.debian.org/security/2021/dsa-4844

https://www.jsof-tech.com/disclosures/dnspooq/

Details

Source: MITRE

Published: 2021-01-20

Updated: 2021-03-26

Type: CWE-122

Risk Information

CVSS v2

Base Score: 7.1

Vector: AV:N/AC:M/Au:N/C:N/I:N/A:C

Impact Score: 6.9

Exploitability Score: 8.6

Severity: HIGH

CVSS v3

Base Score: 5.9

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Impact Score: 3.6

Exploitability Score: 2.2

Severity: MEDIUM