T01 · Skill Instruction Hijacking
- Location
SKILL.md:119- Finding
Untrusted Remote Content Can Hijack the Ingestion Workflow and Generated Skill Instructions
- Content
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Vulnerability Details
File Location:
SKILL.md, lines 119-145 and 213-257
Vulnerability Type: Prompt injection through untrusted content ingestion and instruction synthesis
Risk Level: HighVulnerable Code Snippets
markdown ## The 8-Step Pipeline ### Step 1: READ — Extract Content Execute extraction according to the Strategy chain. Log the successful extraction method. ### Step 2: CLASSIFY — Categorize Assign **1 primary category** + up to 2 tags:markdown ### Step 6: SYNTHESIZE — Auto-Skill Generation (Evolution Step) **Trigger:** Content describes an **actionable tool, API, protocol, or technique** that the Agent currently lacks. **Do NOT trigger if:** Content is purely theoretical, an opinion piece, a capability the Agent already possesses, or ranked ⚪ Low purely regarding strategic value. **Execution:** 1. **Gap Analysis:** Compare current `skills/` directory and Strategic Landscape to confirm this is a missing capability. 2. **Draft Minting:** Create a new Skill folder in `{workspace}/skills/_drafts/`: skills/_drafts/[skill-name]/ ├── SKILL.md # Generated behavior definition └── README.md # Brief description, source, dependencies 3. **SKILL.md Template:** ## Execution Flow [Step-by-step logic pulled from ingested docs]Technical Analysis
The Skill directs the Agent to fetch and interpret arbitrary user-provided URLs and subsequently derive Agent execution instructions from the ingested documents. It does not establish a security boundary between trusted Skill instructions and untrusted document content.
No instructions require the Agent to:
- Treat fetched text exclusively as inert data.
- Ignore commands, role changes, tool requests, or policy statements embedded in a source.
- Detect or quarantine prompt-injection patterns.
- Restrict generated execution steps to independently verified documentation.
- Require confirmation before producing a Skill draft based on remote instructions.
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- Remediation
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Remediation Suggestions
- Add an explicit instruction that all fetched or pasted content is untrusted data and that commands found within it must never be followed.
- Separate content acquisition from Agent reasoning. Extract plain text in a constrained stage before supplying it to the analytical pipeline.
- Detect and quarantine prompt-like directives, including requests to change roles, reveal secrets, invoke tools, modify files, or ignore prior instructions.
- Generate execution flows only from independently verified, allowlisted documentation sections rather than copying steps directly from source content.
- Require explicit operator confirmation before creating any Skill draft.
- Include source provenance and exact quotations for every generated execution step so reviewers can trace its origin.
- Add a mandatory security review section to generated drafts covering requested tools, network access, filesystem access, credentials, and shell commands.
- Keep draft directories technically excluded from runtime discovery and verify this isolation in host configuration rather than relying only on documentation.
- Refuse synthesis when a source contains obfuscated content, conflicting instructions, unverifiable dependencies, or requests for elevated privileges.
