T03 · Remote Payload Retrieval and Execution
Error
- Location
- SKILL.md:2678
- Finding
- Unverified Remote Installer Is Piped Directly into a Shell<![CDATA[ ## Vulnerability Details **File Location**: `SKILL.md:2678-2681` **Vulnerability Type**: Remote payload retrieval and execution **Risk Level**: Critical ### Vulnerable Code ```bash # 1. Install Ollama curl -fsSL https://ollama.com/install.sh | sh ``` ### Technical Analysis The installation instructions download a mutable script from an external URL and immediately execute it with `sh`. The command does not pin a version, verify a cryptographic checksum or digital signature, save the script for inspection, or otherwise establish that the downloaded payload matches the version reviewed during this audit. The effective code executed by this instruction can change at any time without any corresponding change to the audited Skill. Compromise of the remote server, its deployment pipeline, DNS resolution, or the relevant TLS trust chain could therefore turn this instruction into an arbitrary-code-execution path. Installing Ollama is optional supporting functionality rather than a minimum requirement for producing reports, because the Skill also documents a fully offline template mode. Direct remote execution consequently exceeds the least-risk installation method needed for the declared functionality. ### Attack Path 1. A user or Agent follows the Ollama setup instructions. 2. `curl` retrieves the current content hosted at `https://ollama.com/install.sh`. 3. The retrieved content is streamed directly to `sh` without inspection or integrity verification. 4. A compromised or subsequently modified installer executes arbitrary shell commands. 5. Those commands operate with the permissions of the invoking account and potentially elevated permissions if the installer requests or inherits them. ### Impact Assessment Successful exploitation provides arbitrary command execution under the invoking user's privileges. Depending on those privileges and the behavior of the remote installer, an attacker could modify files, install additional software, access user- ...[truncated 215 chars]
- Remediation
- <![CDATA[ ## Remediation Suggestions - Remove the `curl | sh` instruction. - Direct users to an official, versioned package or installer appropriate to their operating system. - If a script must be downloaded, save it locally before execution and verify a publisher signature or a pinned SHA-256 checksum. - Pin the expected Ollama release rather than installing an unspecified current version. - Display the exact artifact and verification result and require explicit user approval before execution. - Run installation in a restricted environment without administrative privileges unless elevation is demonstrably required. - Preserve the existing template-only mode as the default when Ollama is unavailable. ]]>
