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


Severity

Recommended
0.0
high
0
10

Based on Red Hat Enterprise Linux security rating.

Threat Intelligence

EPSS
14.39% (96th percentile)

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  • Snyk IDSNYK-RHEL8-DNSMASQUTILS-3871724
  • published26 Jul 2021
  • disclosed19 Jan 2021

Introduced: 19 Jan 2021

CVE-2020-25682  (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 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.

CVSS Scores

version 3.1