SEC476 / CLAUDE-WRITE-UNSAFE-PATH

SEC476 flags shared Claude settings when permissions.allow grants Write(...) over an absolute path, home-relative path, Windows drive path, or parent-traversing path.

Why It Matters

Shared write permissions outside the repository widen the mutation boundary for every user of the committed Claude policy. Absolute or parent-traversing scopes make it easier for a workflow to modify files that are not part of the reviewed project surface.

Trigger Shape

The rule triggers only when all of these are true:

• the file is a detected Claude settings surface
• the path is not fixture-like
• permissions.allow contains a Write(...) token whose scope is absolute, home-relative, drive-qualified, or parent-traversing

Clean Cases

These stay clean:

• repository-scoped paths such as Write(./artifacts/**)
• permissions that do not grant Write(...)
• fixture-like examples under test or fixture paths

Example Trigger

{
  "permissions": {
    "allow": ["Write(../shared/**)", "Read(./docs/**)"]
  }
}

Safer Example

{
  "permissions": {
    "allow": ["Write(./artifacts/**)", "Read(./docs/**)"]
  }
}

How To Fix

Replace broad Write(...) path grants with repository-scoped allowlists, or remove shared access to absolute, home-relative, or parent-traversing paths from the committed Claude settings file.