Heap-based Buffer Overflow Affecting dnsmasq package, versions <2.82-1ubuntu2


Severity

Recommended
0.0
medium
0
10

Based on Ubuntu security rating.

Threat Intelligence

EPSS
6.56% (94th percentile)

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  • Snyk IDSNYK-UBUNTU2204-DNSMASQ-2777649
  • published19 Jan 2021
  • disclosed20 Jan 2021

Introduced: 19 Jan 2021

CVE-2020-25683  (opens in a new tab)
CWE-122  (opens in a new tab)

How to fix?

Upgrade Ubuntu:22.04 dnsmasq to version 2.82-1ubuntu2 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream dnsmasq package and not the dnsmasq package as distributed by Ubuntu. See How to fix? for Ubuntu:22.04 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. 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.

CVSS Scores

version 3.1