Heap-based Buffer Overflow Affecting dnsmasq package, versions [,2.83)


Severity

Recommended
0.0
high
0
10

CVSS assessment made by Snyk's Security Team. Learn more

Threat Intelligence

EPSS
19.27% (97th percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk IDSNYK-UNMANAGED-DNSMASQ-2335693
  • published12 Jan 2022
  • disclosed20 Jan 2021
  • creditUnknown

Introduced: 20 Jan 2021

CVE-2020-25682  (opens in a new tab)
CWE-122  (opens in a new tab)

How to fix?

Upgrade dnsmasq to version 2.83 or higher.

Overview

Affected versions of this package are vulnerable to Heap-based Buffer Overflow. 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