This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Samba. Authentication is not required to exploit this vulnerability.
The specific flaw exists within the way Samba handles ReportEventW requests. When parsing the data send in the request Samba uses the field 'strings' to create a heap allocation but then uses another field, 'num_of_strings', to write data to the allocation. Because there is no check to see if 'num_of_strings' is smaller than 'strings' this could result in a heap buffer overflow that could lead to remote code execution.