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).
No PoCs from references.
- https://github.com/ARPSyndicate/cvemon
- https://github.com/Live-Hack-CVE/CVE-2019-14907
- https://github.com/ep-infosec/50_google_honggfuzz
- https://github.com/google/honggfuzz
- https://github.com/lllnx/lllnx
- https://github.com/uiop7774/Honggfuzz_mod