A flaw was found in the way samba client before samba 4.4.16, samba 4.5.14 and samba 4.6.8 used encryption with the max protocol set as SMB3. The connection could lose the requirement for signing and encrypting to any DFS redirects, allowing an attacker to read or alter the contents of the connection via a man-in-the-middle attack.
CWE-310 - Cryptographic Issues
Cryptographic issues is a category of weaknesses related to the design and implementation of the confidentiality and integrity of data. If not addressed, the weaknesses in this category can lead to data quality degradation.