Two defenses for tag mode where an attacker with repo write access could
craft a prompt injection payload in an issue/PR to gain RCE on the
Actions runner:
1. git-push wrapper (H1 #3556799)
The Bash(git\ push:*) rule permitted arbitrary flags and remotes,
including combinations that execute shell commands locally. Replaced
with scripts/git-push.sh which allowlists exactly 'origin <ref>' with
no flags, validates the ref via check-ref-format. Same pattern as
scripts/gh.sh.
2. acceptEdits instead of blanket Write/Edit (Asana 1213310082312048)
Edit/MultiEdit/Write in allowedTools granted write access to the
whole runner filesystem (~/.bashrc etc). Removed from allowedTools
and set --permission-mode acceptEdits, which auto-accepts edits
inside cwd ($GITHUB_WORKSPACE) and denies outside. Headless SDK has
no prompt handler so 'ask' becomes deny.
Also:
- Noted that create-prompt/index.ts exports ALLOWED_TOOLS env var that
nothing reads. The live path is modes/tag/index.ts. Mirrored the fix
in both so the file the H1 report likely points to stays in sync.
- Updated prompt text (3 callsites) to reference the wrapper.
- Updated tests (4 prompt-content asserts, 7 tool-list asserts).