T03 · Remote Payload Retrieval and Execution
Error
- Location
SKILL.md:29- Finding
Unverified Remote Installation Script Executed Directly by Bash
- Content
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**Pre-check: Aliyun CLI >= 3.3.3 required** > Run `aliyun version` to verify >= 3.3.3. If not installed or version too low, > run `curl -fsSL https://aliyuncli.alicdn.com/setup.sh | bash` to update, > or see `references/cli-installation-guide.md` for installation instructions. ``` ```bash **[MUST] CLI Installation** (if not already installed or version < 3.3.3): ```bash curl -fsSL https://aliyuncli.alicdn.com/setup.sh | bash aliyun version ``` ``` ### Technical Analysis The Skill downloads a mutable shell script from an external URL and immediately sends the response to Bash. The downloaded content is neither included in the audited package nor pinned to an immutable version. There is no checksum validation, cryptographic signature verification, local inspection step, or content allowlist. HTTPS protects the connection in transit but does not guarantee that the current remote payload is the same payload that was reviewed. Compromise of the hosting account, CDN, DNS resolution, certificate infrastructure, or upstream release process could replace the installer after the Skill has passed review. The behavior is marked as mandatory when the CLI is missing or outdated. It is not necessary to pipe remote content directly into a shell to provide the declared Elasticsearch network-management functionality. ### Attack Path 1. An attacker compromises or redirects `aliyuncli.alicdn.com`, its CDN distribution, or the upstream installer publication process. 2. The attacker replaces `setup.sh` with a modified script. 3. The Skill detects that Aliyun CLI is missing or older than version 3.3.3. 4. Following the mandatory instruction, the agent or user runs the `curl | bash` pipeline. 5. Bash executes the attacker-controlled response with all privileges availabl ...[truncated 1003 chars]- Remediation
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