CVE-2021-22212
mediumpriority · track · 30OT risk · elevatedEPSS 0.005 · 44 %ileEURUUSEPSS · scored 2026-10-27
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.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 4–7.4
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (6)
Products and version ranges known to be affected.
also known as (4)
Other names and identifiers for this entity.
sources
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references (12)
External citations — patches, advisories, analysis.
- https://bugzilla.redhat.com/show_bug.cgi?id=1955859cnnvd
- https://gitlab.com/NTPsec/ntpsec/-/issues/699cnnvd
- https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-22212.jsoncnnvd
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/3GIT2HYL5BQXPGKI6ZDNG473IEQ5WQF2/cnnvd
- https://bugzilla.redhat.com/show_bug.cgi?id=1955859enisa_euvd
- https://gitlab.com/NTPsec/ntpsec/-/issues/699enisa_euvd
- https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-22212.jsonenisa_euvd
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3GIT2HYL5BQXPGKI6ZDNG473IEQ5WQF2/enisa_euvd
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