T03 · Remote Payload Retrieval and Execution
- Location
SETUP.md:62- Finding
Unverified Remote Installer Is Executed Directly by the Shell
- Content
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Vulnerability Details
File Location:
SETUP.md, line 62
Vulnerability Type: Remote payload retrieval and execution
Risk Level: HighVulnerable Code:
bash curl -LsSf https://astral.sh/uv/install.sh | shTechnical Analysis
The setup instructions retrieve a mutable script from an external URL and pipe the response directly into
sh. The script is executed before the user can inspect it, and the command does not pin a release, verify a cryptographic signature, or validate a checksum.HTTPS provides transport protection but does not establish that the current remote script is immutable or safe. The effective code executed during installation can change after this skill has been audited. Compromise of the upstream website, hosting environment, DNS resolution, certificate issuance, or release process could therefore convert this installation command into arbitrary code execution.
Installing
uvmay be necessary for the documented PDF export workflow, but executing an unverified network response is not the minimum privilege or safest installation mechanism needed to obtain that dependency.Attack Path
- An attacker compromises or gains control over the remote installer delivery path.
- The attacker modifies the response served from
https://astral.sh/uv/install.sh. - A user follows the setup instructions and runs the documented command.
curldownloads the attacker-controlled response and sends it directly tosh.- The shell executes the payload with the privileges of the user running setup.
- The payload can read or modify files accessible to that user, including workspace data, shell configuration, and user-readable credentials.
Impact Assessment
Successful exploitation provides arbitrary command execution under the installing user's account. The payload could access the user's files and environment, steal credentials available to that account, alter shell startup fil ...[truncated 160 chars]
- Remediation
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Remediation Suggestions
- Do not pipe network responses directly into a shell.
- Prefer a trusted operating-system package manager with a pinned package version.
- If an upstream installer is required, download a version-specific artifact to a local file first.
- Verify the artifact using a cryptographic signature or a checksum obtained through an independently authenticated channel.
- Present the downloaded script for inspection before execution.
- Execute installation with ordinary user privileges and avoid
sudounless a specific system-level operation requires it. - Document the exact expected version, hash, source, and verification commands so the installed dependency is reproducible and auditable.
