T03 · Remote Payload Retrieval and Execution
Error
- Location
- scripts/bootstrap.sh:4
- Finding
- Unpinned Remote Repository Is Downloaded and Executed## Vulnerability Details **File Location**: `scripts/bootstrap.sh`, lines 4-16 **Vulnerability Type**: Mutable remote payload retrieval and execution **Risk Level**: High ### Vulnerable Code ```bash PARAKEET_DIR="${PARAKEET_DIR:-$HOME/parakeet-asr}" REPO_URL="${PARAKEET_REPO_URL:-https://github.com/rundax/parakeet-asr.git}" if [ -d "$PARAKEET_DIR/.git" ]; then echo "Updating existing repo at $PARAKEET_DIR" git -C "$PARAKEET_DIR" pull --ff-only else echo "Cloning repo to $PARAKEET_DIR" git clone "$REPO_URL" "$PARAKEET_DIR" fi cd "$PARAKEET_DIR" ./setup.sh ``` ### Technical Analysis The bootstrap script clones or updates a third-party Git repository and immediately executes its `setup.sh` file. The retrieved revision is not pinned to an audited commit, and the script does not verify a cryptographic checksum, commit signature, or signed release. Although `git pull --ff-only` prevents a non-fast-forward merge, it does not establish trust in newly retrieved commits. The effective installation payload can therefore change after this Skill has been reviewed. In addition, the `PARAKEET_REPO_URL` environment variable permits the repository source to be replaced with another Git repository. This is a supply-chain execution boundary: the audited local script delegates code execution to mutable content that is not included in the audited project. ### Attack Path 1. An attacker compromises or maliciously modifies the upstream repository, its active branch, or a repository selected through `PARAKEET_REPO_URL`. 2. A user or agent follows the documented workflow and runs: ```bash bash scripts/bootstrap.sh ``` 3. The script clones the attacker-controlled repository or pulls its latest commits. 4. No expected commit ID, signature, or checksum is validated. 5. The downloaded `setup.sh` executes with the permissions of the user running the bootstrap script. 6. The remote setup code can perform any operation available to that user and may request or invok ...[truncated 651 chars]
- Remediation
- ## Remediation Suggestions 1. Pin the upstream source to a specific, previously audited commit hash rather than pulling the current branch tip. 2. Verify that the checked-out `HEAD` exactly matches the expected commit before executing any file: ```bash EXPECTED_COMMIT="approved-full-commit-hash" git clone --no-checkout "$REPO_URL" "$PARAKEET_DIR" git -C "$PARAKEET_DIR" checkout --detach "$EXPECTED_COMMIT" test "$(git -C "$PARAKEET_DIR" rev-parse HEAD)" = "$EXPECTED_COMMIT" ``` 3. Prefer a signed release artifact and validate its cryptographic signature and SHA-256 checksum against values stored in the reviewed Skill. 4. Do not run `git pull` followed by automatic execution. Updates should require explicit review and an intentional revision change. 5. Reject `PARAKEET_REPO_URL` overrides by default, or require explicit user confirmation while displaying the resolved source and revision. 6. Inspect and present the downloaded setup actions before execution, especially package-manager commands, privilege requests, service installation, and network listeners. 7. Execute installation with the least-privileged account possible and avoid granting elevated privileges to unverified remote code.