CVE 2015-5370
Samba 3.x and 4.x before 4.2.11, 4.3.x before 4.3.8, and 4.4.x before 4.4.2 does not properly implement the DCE-RPC layer, which allows remote attackers to perform protocol-downgrade attacks, cause a denial of service (application crash or CPU consumption), or possibly execute arbitrary code on a client system via unspecified vectors.
See the 
CVE page on Mitre.org
for more details.
