ZKTeco ZKBio CVSecurity 6.1.1 is vulnerable to Directory Traversal via photoBase64. An unauthenticated user can download local files from the server. NOTE: Third parties have indicated other versions are also vulnerable including up to 6.4.1.
The product uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize 'dir\..\..\filename' (multiple internal backslash dot dot) sequences that can resolve to a location that is outside of that directory.