Parsing modern ASP.NET Core Identity password hashes to Hashcat
While this would not be anything out of the ordinary, the environment certainly was. So where do we expect ASP.NET Core Identity hashes? Some obscure cloud application, local Windows application, ... but surely not on an embedded linux system!?
While the vulnerability itself was discovered at this point - exposing password hashes without any authentication is not exactly considered best practice - it was decided to investigate the password hashes further in an attempt to showcase password cracking and detect weak passwords.
Despite numerous tools on the internet advertising the capability of converting ASP.NET Core Identity hashes into Hashcat format, all attempts at cracking the extracted password hashes remained unsuccessful despite knowing some pairs of plaintext passwords and ASP.NET Core Identity hashes.
Why? It was time to dig in!