An information disclosure vulnerability exists when Visual Studio improperly discloses limited contents of uninitialized memory while compiling program database (PDB) files. An attacker who took advantage of this information disclosure could view uninitialized memory from the Visual Studio instance used to compile the PDB file. To take advantage of the vulnerability, an attacker would require access to an affected PDB file created using a vulnerable version of Visual Studio. An attacker would have no way to force a developer to produce this information disclosure. The security update addresses the vulnerability by correcting how PDB files are generated when a project is compiled.

Mateusz Jurczyk of Google Project Zero