T03 · Remote Payload Retrieval and Execution
Error
- Location
- SKILL.md:45
- Finding
- Unpinned Remote dotLottie Script Permits Mutable Code Execution## Vulnerability Details **File Location**: `SKILL.md`, line 45 **Vulnerability Type**: Unpinned remote JavaScript dependency **Risk Level**: High ```html <script src="https://unpkg.com/@lottiefiles/dotlottie-web"></script> ``` ### Technical Analysis The documented pattern loads executable JavaScript directly from unpkg without specifying an exact package version or a Subresource Integrity hash. The URL can consequently resolve to different package releases over time, allowing the effective code executed by generated pages to change after the Skill has been audited. This creates a remote payload execution channel. Compromise of the package publisher, npm package, CDN infrastructure, or a future package release could cause attacker-controlled JavaScript to execute in every page that adopts this example. The project provides no local verification mechanism that would detect such a change. ### Attack Path 1. A developer or agent copies the documented dotLottie integration pattern into a generated page. 2. A package publisher account, package release, or upstream distribution channel is compromised, or a malicious version becomes the version selected by the unpinned URL. 3. A browser requests the mutable unpkg URL when loading the page. 4. The browser receives and executes the modified JavaScript without validating its expected content. 5. The injected script operates with the JavaScript privileges of the affected page and can access data and APIs available to that page. ### Impact Assessment Successful exploitation permits arbitrary client-side JavaScript execution in pages using the pattern. The payload could read or modify page content, access non-`HttpOnly` browser storage and tokens available to the origin, intercept application interactions, issue authenticated same-origin requests, or alter animation and rendering behavior. The exact scope is limited by the page's origin, Content Security Policy, browser isolation ...[truncated 193 chars]
- Remediation
- ## Remediation Suggestions - Pin the dependency to an exact, reviewed version rather than relying on the package's default version. - Prefer vendoring the audited JavaScript file in the local project so rendering does not depend on remote executable content. - If remote hosting is unavoidable, use a version-specific immutable URL and add a verified Subresource Integrity hash with `crossorigin="anonymous"`. - Apply a restrictive Content Security Policy that permits scripts only from explicitly trusted sources and avoids `unsafe-inline` where feasible. - Add dependency update review and integrity verification to the maintenance process.