All samba versions 4.9.x before 4.9.18, 4.10.x before 4.10.12 and 4.11.x before 4.11.5 have an issue where if it is set with "log level = 3" (or above) then the string obtained from the client, after a failed character conversion, is printed. Such strings can be provided during the NTLMSSP authentication exchange. In the Samba AD DC in particular, this may cause a long-lived process(such as the RPC server) to terminate. (In the file server case, the most likely target, smbd, operates as process-per-client and so a crash there is harmless).
https://www.samba.org/samba/security/CVE-2019-14907.html
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-14907
https://security.netapp.com/advisory/ntap-20200122-0001/
https://www.synology.com/security/advisory/Synology_SA_20_01
https://usn.ubuntu.com/4244-1/
http://lists.opensuse.org/opensuse-security-announce/2020-01/msg00055.html
https://security.gentoo.org/glsa/202003-52
https://lists.debian.org/debian-lts-announce/2021/05/msg00023.html
Source: MITRE
Published: 2020-01-21
Updated: 2022-11-16
Type: CWE-125
Base Score: 2.6
Vector: AV:N/AC:H/Au:N/C:N/I:N/A:P
Impact Score: 2.9
Exploitability Score: 4.9
Severity: LOW
Base Score: 6.5
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Impact Score: 3.6
Exploitability Score: 2.8
Severity: MEDIUM