Heap-based Buffer Overflow Affecting dnsmasq-utils package, versions <0:2.79-11.el8_2.2


Severity

Recommended
high

Based on Red Hat Enterprise Linux security rating.

Threat Intelligence

EPSS
11.62% (96th percentile)

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  • Snyk IDSNYK-RHEL8-DNSMASQUTILS-3878377
  • published26 Jul 2021
  • disclosed19 Jan 2021

Introduced: 19 Jan 2021

CVE-2020-25687  (opens in a new tab)
CWE-122  (opens in a new tab)

How to fix?

Upgrade RHEL:8 dnsmasq-utils to version 0:2.79-11.el8_2.2 or higher.
This issue was patched in RHSA-2021:0151.

NVD Description

Note: Versions mentioned in the description apply only to the upstream dnsmasq-utils package and not the dnsmasq-utils package as distributed by RHEL. See How to fix? for RHEL:8 relevant fixed versions and status.

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.

CVSS Scores

version 3.1