CVE-2021-22212

Name: CVE-2021-22212
Creator: NVD / NIST
Published: 2021-06-08T13:15:07.567+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.4/10EPSS 0.52%

Last modified Jun 17, 2026

CVE-2021-22212 is a high-severity vulnerability rated 7.4/10 on the CVSS scale. ntpkeygen can generate keys that ntpd fails to parse. NTPsec 1.2.0 allows ntpkeygen to generate keys with '#' characters. EPSS estimates a 0.52% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

7.4/10

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

EPSS Probability

0.52%

40.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-327

Affected Software

Vendor	Product	Versions
Ntpsec	Ntpsec	1.2.0
Fedoraproject	Fedora	34

References

https://bugzilla.redhat.com/show_bug.cgi?id=1955859Issue Tracking, Patch, Third Party Advisory
https://gitlab.com/NTPsec/ntpsec/-/issues/699Issue Tracking, Patch, Third Party Advisory
https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-22212.jsonThird Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3GIT2HYL5BQXPGKI6ZDNG473IEQ5WQF2/
https://bugzilla.redhat.com/show_bug.cgi?id=1955859Issue Tracking, Patch, Third Party Advisory
https://gitlab.com/NTPsec/ntpsec/-/issues/699Issue Tracking, Patch, Third Party Advisory
https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-22212.jsonThird Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3GIT2HYL5BQXPGKI6ZDNG473IEQ5WQF2/

Timeline

Published: Jun 8, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-22212?

How severe is CVE-2021-22212?

CVE-2021-22212 has a CVSS score of 7.4/10 (HIGH severity). The EPSS model estimates a 0.52% probability of exploitation in the next 30 days.

How do I fix CVE-2021-22212?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-22212?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST