T08 · Insecure Dependencies
Warning
- Location
- SKILL.md:35
- Finding
- Unpinned Package Execution Through npx## Vulnerability Details **File Location**: `SKILL.md`, line 35 **Vulnerability Type**: Supply-chain risk caused by an unpinned executable dependency **Risk Level**: Medium ### Vulnerable Code ```sh npx skills add powmcp/skills --skill produce-client-site-handoff-report ``` ### Technical Analysis The documented installation command invokes `npx` without pinning the `skills` package to a reviewed version or integrity hash. Depending on the local package-manager state, `npx` can download the package from the configured registry and execute its current release. This creates a mutable execution boundary: the code run by a user may differ from the code that existed when this Skill was reviewed. Compromise of the package, its publisher account, or the configured package registry could therefore introduce attacker-controlled installation behavior. The issue is limited to users who run this installation command. The audit found no evidence that the Skill silently invokes the command, and no bundled malicious script was identified. ### Attack Path 1. An attacker compromises the package publisher, package distribution channel, or registry resolution path for the unversioned `skills` package. 2. The attacker publishes a malicious release or causes the package name to resolve to attacker-controlled content. 3. A user follows `SKILL.md` and runs the documented `npx skills add ...` command. 4. `npx` retrieves the current, unreviewed package release. 5. Package entry-point or installation code executes with the privileges of the invoking user. 6. The malicious package can access resources available to that user and modify files permitted by the user's operating-system permissions. ### Impact Assessment Successful exploitation could provide arbitrary code execution under the invoking user's account. The resulting scope could include reading or changing user-accessible files, accessing credentials exposed to the process, modifying local development configuration, or i ...[truncated 656 chars]
- Remediation
- ## Remediation Suggestions 1. Pin the executable package to a specific, reviewed version, for example by using the package manager's exact-version syntax rather than resolving the latest release. 2. Use a lockfile and verified integrity metadata where supported. 3. Document the exact expected registry and package identity to reduce dependency-confusion and registry-substitution risk. 4. Prefer a reviewed local installation over automatic download-and-execute behavior. 5. Instruct users to inspect the resolved package version and provenance before running it. 6. Establish a controlled update process in which new dependency versions are reviewed and tested before the documented pin is changed. 7. Avoid recommending elevated execution and explicitly state that the installation command should run with ordinary user privileges.