T03 · Remote Payload Retrieval and Execution
Error
- Location
- SKILL.md:6
- Finding
- Unverified Remote Installer Is Executed Directly Through Bash## Vulnerability Details **File Location**: `SKILL.md:6` and `SKILL.md:22-25` **Vulnerability Type**: Remote payload retrieval and execution **Risk Level**: High ### Vulnerable Code ```yaml installation: curl -fsSL https://sherry.hweyukd.top/skills/install-skills.sh | bash ``` ```bash # One-click install curl -fsSL https://sherry.hweyukd.top/skills/install-skills.sh | bash ``` ### Technical Analysis The documented installation procedure pipes the current HTTP response directly into Bash. The installer is not pinned to an immutable release and is not verified using a cryptographic signature or expected checksum. HTTPS protects the connection in transit but does not protect users if the hosting server, domain, deployment process, or upstream installer itself is compromised. The effective code executed by users can therefore change after the reviewed Skill package was published. ### Attack Path 1. An attacker compromises the server, DNS, deployment account, or hosted installer at `sherry.hweyukd.top`. 2. The attacker replaces `install-skills.sh` with a malicious script. 3. A user follows the documented one-click installation command. 4. `curl` retrieves the attacker-controlled response. 5. Bash executes the response immediately, without review or integrity validation. 6. The payload runs with all permissions available to the installing user. ### Impact Assessment Successful exploitation provides arbitrary command execution under the installing user's account. Depending on that account's privileges, the attacker could read or alter workspace files, credentials, Agent configuration, scheduled tasks, and other user-accessible data. Installation under a privileged account would substantially increase the potential system-wide impact.
- Remediation
- ## Remediation Suggestions - Remove all recommendations to execute remote responses through `curl | bash`. - Publish versioned, immutable release artifacts. - Require users to download the installer before reviewing and running it. - Publish and verify a SHA-256 or stronger checksum over every release artifact. - Prefer cryptographic release signatures whose public verification key is distributed through a separate trusted channel. - Document the exact files and system changes the installer will make. - Run installation with the lowest-privileged account capable of completing the task.
