CVE-2021-22212
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 '#'.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.52%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 7.4 HIGHCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
- EPSS
- 0.52% probability · 43th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-327
- Affected
- ntpsec/ntpsec · fedoraproject/fedora
- Source
- cve@gitlab.com
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/
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.