Thread

1. mikestew · 1790117337 · focus · HN ↗

   Here’s my problem with reviving FoxPro in any form: there’s a huge security hole in the Database Container (DBC) design. For DBCs to be useful, they must be read/write to all users (there is no permissions scheme). DBCs have stored procedures that can run any FoxPro code, including Win32 calls made from the FoxPro runtime. The stored procedures are stored as plain text in a “memo” field. Do you see where this is going? With a little technical knowledge, one can modify that INSERT trigger to whatever you like. EDIT: as the DB is just files in the file system, modifications can be made using a text editor, bypassing any checks in the FoxPro runtime. FoxPro just executes what it finds in there.

   My recommendation is to get rid of the DBF/DBC files and move to a SQL DB of some flavor ASAP. If you have the source code, use ODBC or OLE DB to point to a server.

   Source: filed that bug over 20 years ago when I worked on the Fox team. No, it wasn’t going to get fixed without rewriting large parts of how the DB engine worked.

   1. userbinator · 1790122992 · focus · HN ↗

      there is no permissions scheme

      If you already have full access by design, then there's no "huge security hole" either.

      1. EvanAnderson · 1790123702 · focus · HN ↗

         Exactly. It's not a security hole. It's just the architecture of the program.

         It seems like many people have a hard time understanding this, including developers.

         Any attempt to add any kind of permissions, security, etc, without addressing the nature of the architecture (that the database engine runs in the same address space / security context as the UI) misses the point.

         1. shermantanktop · 1790131812 · focus · HN ↗

            You’re saying it’s not a 2 tier client/server app, it’s a one tier app with no intermediate API to define or enforce permissions. Fine.

            But the filesystem access to read/write the db files creates a path to bypass half of that application.

            Does the application checksum the db file and have any resistance to filesystem tampering? That'd be trivial to beat, I’m sure, but it’d be something.

            1. aforwardslash · 1790135212 · focus · HN ↗

               Well, on a different note, if you have a scripted language application, you typically can edit files and bypass whatever you want on the application. In fact, I'd bet most modern software isn't signed; and even if it is, sometimes the libraries that get compiled in into that signed binary... aren't.

               I can change the behaviour of many/most applications by just having read/write access to files; Can you give me examples of mainstream applications that are resistant to filesystem tampering when eg.you have install access? Maybe I'm missing something.

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