CVE-2021-22212

Publication date 8 June 2021

Last updated 25 August 2025

Ubuntu priority

Cvss 3 Severity Score

Description

ntpkeygen can generate keys that ntpd fails to parse. NTPsec 1.2.0 allows ntpkeygen to generate keys with '#' characters. ntpd then either pads, shortens the key, or fails to load these keys entirely, depending on the key type and the placement of the '#'. This results in the administrator not being able to use the keys as expected or the keys are shorter than expected and easier to brute-force, possibly resulting in MITM attacks between ntp clients and ntp servers. For short AES128 keys, ntpd generates a warning that it is padding them.

Status

Show unmaintained releases

Package	Ubuntu Release	Status
ntpsec	24.10 oracular	Not affected
	24.04 LTS noble	Not affected
	23.10 mantic	Ignored end of life, was needs-triage
	23.04 lunar	Ignored end of life, was needs-triage
	22.10 kinetic	Ignored end of life, was needs-triage
	22.04 LTS jammy	Not affected
	21.10 impish	Ignored end of life
	21.04 hirsute	Ignored end of life
	20.10 groovy	Ignored end of life
	20.04 LTS focal	Not affected
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Ignored end of standard support
	14.04 LTS trusty	Not in release

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
ntpsec	Upstream: fc50a70

Severity score breakdown

Parameter	Value
Base score	7.4 · High
Attack vector	Network
Attack complexity	High
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality	High
Integrity impact	High
Availability impact	None
Vector	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N