SteamAppData.vdf should be completely encrypted, it contains sensitive information, an exploit based on this has been available to anyone using metasploit for a long time.
This repo is for problems in the Linux and Mac ports of the Steam client. You're describing a general issue and that can be passed on but this isn't really the direct route.
SteamAppData.vdf should be completely encrypted, it contains sensitive information, an exploit based on this has been available to anyone using metasploit for a long time.