T03 · Remote Payload Retrieval and Execution
Error
- Location
- README.md:18
- Finding
- Documentation Executes Mutable Remote Installer Scripts Without Integrity Verification## Vulnerability Details **File Location**: `README.md:18-27`; duplicated in `README.zh-CN.md:18-27` **Vulnerability Type**: Remote payload retrieval and immediate execution **Risk Level**: Critical ### Vulnerable Code ```bash **macOS and Linux:** ```bash curl -LsSf https://astral.sh/uv/install.sh | sh ``` **Windows:** ```powershell powershell -ExecutionPolicy ByPass -c "irm https://astral.sh/uv/install.ps1 | iex" ``` ``` The same commands appear in both the English and Chinese installation guides. ### Technical Analysis These installation instructions retrieve mutable content from an external URL and pass it directly to a command interpreter. The Unix command pipes the HTTP response into `sh`, while the Windows command evaluates the response through `iex` and explicitly bypasses PowerShell execution-policy restrictions. The commands provide no opportunity to inspect the downloaded scripts and perform no version pinning, checksum validation, or cryptographic signature verification. Consequently, the code that users execute can differ from the code available when this Skill was audited. The domains shown appear to be official Astral infrastructure, but the repository itself provides no mechanism to establish the integrity of a particular installer payload. A compromise involving the remote hosting service, release process, DNS resolution, or another part of the delivery chain could therefore turn the documented prerequisite installation into arbitrary local code execution. Installing `uv` is relevant to the Skill's declared operation. However, directly executing unverified network content exceeds the minimum-risk approach necessary to install that dependency. ### Attack Path 1. A user follows the prerequisite installation instructions in either README. 2. The command requests a mutable installer from the external Astral endpoint. 3. The remote endpoint or its delivery chain supplies malicious or compromis ...[truncated 984 chars]
- Remediation
- ## Remediation Suggestions 1. Remove instructions that pipe downloaded content directly into `sh` or `iex`. 2. Prefer an operating-system package manager or another installation channel that supports signed and versioned packages. 3. If a standalone installer is necessary: - Pin a specific release and artifact URL. - Download the artifact to disk without executing it. - Publish the expected SHA-256 digest in the documentation. - Verify the digest or a trusted cryptographic signature before execution. - Allow users to inspect the downloaded content. 4. Remove the PowerShell `-ExecutionPolicy ByPass` instruction. 5. Apply the same changes to both `README.md` and `README.zh-CN.md`. 6. Document the exact supported `uv` version so installations are reproducible and auditable.