T03 · Remote Payload Retrieval and Execution
Error
- Location
- SKILL.md:61
- Finding
- Unverified Remote Installer Download and Immediate Execution## Vulnerability Details **File Location**: `SKILL.md`, lines 61–65 **Vulnerability Type**: Remote payload retrieval and execution **Risk Level**: High ### Vulnerable Code ```bash curl -fsSL https://cli.oomol.com/install.sh | bash # macOS / Linux ``` ```powershell irm https://cli.oomol.com/install.ps1 | iex # Windows PowerShell ``` ### Technical Analysis The installation instructions download mutable scripts from `cli.oomol.com` and immediately execute the returned content through Bash or PowerShell. The process does not pin an installer version, verify a cryptographic signature or checksum, or provide an opportunity to inspect the downloaded script before execution. Although the URL uses HTTPS and an OOMOL-branded domain, the remote scripts are not included in the audited project. Their effective behavior can therefore change after this Skill has been reviewed. Compromise of the hosting infrastructure, publishing account, DNS or TLS trust path, or installer deployment process could cause arbitrary attacker-controlled commands to be executed. This behavior is not required for the Skill's core read-only Fern functionality. Installing a prerequisite may be necessary when the CLI is absent, but immediate execution of unverified remote content exceeds the minimum privilege and trust necessary to perform that installation safely. ### Attack Path 1. The `oo` CLI is unavailable, causing the documented first-time setup condition to apply. 2. An agent or user follows the installation command in `SKILL.md`. 3. The remote installer source or its delivery infrastructure has been compromised, or the hosted script has otherwise been replaced. 4. `curl` or `Invoke-RestMethod` retrieves the modified payload. 5. The shell pipeline passes the response directly to `bash` or `iex` without integrity validation or inspection. 6. The malicious payload executes with the privileges of the user running the command. ### Im ...[truncated 862 chars]
- Remediation
- ## Remediation Suggestions 1. Remove both pipe-to-shell installation commands. 2. Direct users to a documented official release page or trusted platform package manager. 3. Pin the CLI to a specific reviewed version rather than downloading a mutable latest installer. 4. Publish signed release artifacts and verify their cryptographic signatures before installation. If signatures are unavailable, publish and validate a version-specific SHA-256 checksum over HTTPS through an independently protected release channel. 5. Download the installer to a local file, verify it, and allow inspection before executing it as a separate step. 6. Require explicit user approval before installing software or executing any downloaded installer. 7. Run installation with ordinary user privileges unless elevated privileges are demonstrably required, and document any files, network access, or configuration changes the installer performs. 8. Prefer instructions such as the following general sequence: - Download a version-pinned artifact. - Validate its signature or pinned checksum. - Inspect or display the installer source where practical. - Execute it only after successful verification and explicit approval.