T08 · Insecure Dependencies
Warning
- Location
- SKILL.md:5
- Finding
- Unpinned Executable Installation from a Mutable Third-Party Homebrew Tap## Vulnerability Details **File Location**: `SKILL.md`, line 5 **Vulnerability Type**: `T08: Insecure Dependencies` **Risk Level**: Medium **Complete Code Snippet**: ```yaml metadata: {"clawdbot":{"emoji":"🔱","requires":{"bins":["caseclaw"]},"install":[{"id":"brew","kind":"brew","formula":"legal-tools/tap/caseclaw","bins":["caseclaw"],"label":"Install caseclaw (brew)"}]}} ``` ### Technical Analysis The skill instructs the host environment to install the `caseclaw` executable from the external Homebrew formula `legal-tools/tap/caseclaw`. The dependency is referenced through a mutable package name without an immutable source commit, fixed package version, checksum, or cryptographic signature recorded in the audited project. Neither the Homebrew formula nor the executable's source is included in the project, which contains only `SKILL.md` and `_meta.json`. Therefore, the behavior and integrity of the code ultimately executed as `caseclaw` cannot be verified from this artifact. A future update to the tap, compromise of its publishing account or repository, or compromise of an upstream release could change the installed payload after this skill has been reviewed. This is a supply-chain weakness rather than evidence that the current external package is malicious. ### Attack Path 1. An attacker compromises the `legal-tools/tap` repository, its publishing credentials, the referenced formula, or an upstream artifact used by that formula. 2. The attacker changes the formula or upstream release so that it installs a malicious `caseclaw` executable. 3. A user loads or installs the skill in an environment where `caseclaw` is not already available. 4. The skill's installation metadata causes Homebrew to resolve the mutable `legal-tools/tap/caseclaw` formula. 5. Because this project specifies no trusted version or expected digest, the modified package may be accepted and installed without detection by the skill. 6. The user later in ...[truncated 1120 chars]
- Remediation
- ## Remediation Suggestions 1. Pin the dependency to a reviewed, immutable release rather than relying solely on a mutable Homebrew formula name. 2. Record and verify a SHA-256 digest or a trusted cryptographic signature for the downloaded artifact before installation. 3. Pin the Homebrew tap or formula source to an immutable commit and ensure that the formula itself verifies the integrity of its upstream archive. 4. Include the formula and executable source in the auditable package, or provide reproducible-build documentation that allows reviewers to map the installed binary to reviewed source. 5. Protect release and tap publishing workflows with multi-factor authentication, least-privilege tokens, protected branches, mandatory review, signed tags, and provenance attestations. 6. Fail closed if signature, checksum, provenance, package version, or source verification does not match the approved release. 7. Display the exact package version and source to the user and require explicit confirmation before installing an executable that will process confidential legal data. 8. Run the executable with least privilege and restrict its filesystem and network access where practical. 9. Independently review the external formula and executable before treating the package's documented security, storage, or network-processing claims as verified.