An information disclosure vulnerability exists in the way that the Microsoft Server Message Block 2.0 (SMBv2) server handles certain requests. An attacker who successfully exploited this vulnerability could craft a special packet, which could lead to information disclosure from the server.
To exploit the vulnerability, in most situations, an unauthenticated attacker could send a specially crafted packet to a targeted SMBv2 server.
The security update addresses the vulnerability by correcting how SMBv2 handles these specially crafted requests.