GHSA-cc2g-gq8c-r332 grok-faf-mcp has an arbitrary local file read via unconfined `path` argument in FAF tools

• npm grok-faf-mcp: < 1.5.3 → fixed in 1.5.3

Summary Several `grok-faf-mcp` MCP tools accept a caller-controlled `path` argument and resolve it (`~` expansion + `path.resolve()`) straight into a filesystem read without confining it to a trusted project directory. An absolute path or `../` traversal is resolved and used as-is, so the server process can be made to read files outside the intended `.faf` project context. The only remaining limit is OS file permissions. Affected tools `refresh_faf`, `faf_score`, `faf_get_orchestration_policy`, `refresh_blend` (and the shared `getProjectPath()` chokepoint feeding the `.faf` tools), plus the general-purpose `faf_read` / `faf_write` file tools (denylist-only; an absolute path still reached home-directory secrets, and `faf_write` could write outside the project). `refresh_faf` echoes the file contents verbatim back to the caller as "fresh DNA"; `faf_get_orchestration_policy` reflects values parsed out of the attacker-chosen file and echoes the resolved absolute path — confirming the read. Impact An MCP client — or an LLM prompt-injected via attacker-controlled content (a web page, README, ticket, or `.faf`) into issuing a tool call — can read any file the server process can read: SSH keys (`~/.ssh/id_rsa`), cloud credentials (`~/.aws/credentials`), `.env` files, source, `/etc/passwd`. This is a sensitive-information-disclosure (CWE-200) primitive that far exceeds the declared `.faf` project-context scope. The server runs over stdio, so the read is reached by a crafted tool call (e.g. a prompt-injected agent processing attacker-controlled content). Patches Fixed in 1.5.3 by confining every caller-supplied `path` before any filesystem access (`safe-path.ts`): • Reads are restricted to `.faf` / `.fafm` context files, so non-context files (secrets) are refused regardless of directory. • General file ops (`faf_read` / `faf_write`) are confined to the project root (cwd + system temp; override with `FAF_ALLOWED_ROOTS`). • Paths are canonicalized through symlinks (closing the symlink bypass); absolute paths and `../` escapes are rejected. Upgrade: `npm install -g [email protected]` (or `bunx grok-faf-mcp`). Workarounds If you cannot upgrade immediately, run the server only against trusted local projects, and set `FAF_ALLOWED_ROOTS` (patched versions) to a single project directory for a hard directory boundary. Credits Discovered and responsibly reported via coordinated disclosure by Zhihao Zhang (Worcester Polytechnic Institute).