CVE-2020-25682

Publication date 19 January 2021

Last updated 24 July 2024

Ubuntu priority

Cvss 3 Severity Score

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.

Status

Show unmaintained releases

Package	Ubuntu Release	Status
dnsmasq	24.10 oracular	Fixed 2.82-1ubuntu2
	24.04 LTS noble	Fixed 2.82-1ubuntu2
	23.10 mantic	Fixed 2.82-1ubuntu2
	23.04 lunar	Fixed 2.82-1ubuntu2
	22.10 kinetic	Fixed 2.82-1ubuntu2
	22.04 LTS jammy	Fixed 2.82-1ubuntu2
	21.10 impish	Fixed 2.82-1ubuntu2
	21.04 hirsute	Fixed 2.82-1ubuntu2
	20.10 groovy	Fixed 2.82-1ubuntu1.1
	20.04 LTS focal	Fixed 2.80-1.1ubuntu1.2
	18.04 LTS bionic	Fixed 2.79-1ubuntu0.2
	16.04 LTS xenial	Fixed 2.75-1ubuntu0.16.04.7
	14.04 LTS trusty	Needs evaluation

Severity score breakdown

Parameter	Value
Base score	8.1 · High
Attack vector	Network
Attack complexity	High
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality	High
Integrity impact	High
Availability impact	High
Vector	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

References

Related Ubuntu Security Notices (USN)