ildasm.exe will show it if you double-click on "MANIFEST" and look for "Metadata version". By default, it's the version that the image was compiled against.
In AssemblyInfo there are two assembly versions:
AssemblyVersion: Specify the version of the assembly being attributed.
AssemblyFileVersion: Instructs a compiler to use a specific version number for the Win32 file version resource. The Win32 file version is not required to …
There are three assembly version attributes. What are differences? Is it ok if I use AssemblyVersion and ignore the rest?
MSDN says:
AssemblyVersion:
Specifies the version of the assembly being attributed.
AssemblyFileVersion:
Instructs a compiler to use a specific version …