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Security audit

Using Skillet

Security checks for vulnerabilities and agentic risk

Overview

This workflow guide needs review because it tells the agent to place project files and skills above its governing system instructions.

Before installing, request a version that explicitly preserves system and developer instructions above user, project, and skill guidance. Review companion skills separately before granting their requested access.

Vulnerability Patterns
  • Skill Instruction HijackingAlters the agent's session goals or safety constraints when the skill loads
  • Agent Memory PoisoningWrites attacker-controlled rules into memory that affect later sessions
  • Remote Payload Retrieval and ExecutionFetches external code whose behavior can change after review
  • Embedded Malicious CodeShips malicious scripts inside the skill and executes them locally
  • Unauthorized Access and Privilege EscalationObtains permissions beyond the task's legitimate needs
Findings (1)

T01 · Skill Instruction Hijacking

Error
Location
SKILL.md
Finding

Explicit inversion of the agent's instruction hierarchy

Content
View full analysis

Impact

If followed, this rule defeats system-level constraints whenever conflicting skill or user instructions arise. The audit establishes the explicit bypass instruction, not successful exploitation against a particular host.

Vulnerability Patterns
  • Prompt InjectionInstruction Override, Hidden Instructions, Exfiltration Commands
  • Excessive AgencyUnrestricted Tool Access, Autonomous Decision Making, Scope Creep
  • Data ExfiltrationExternal Transmission, Env Variable Harvesting, File System Enumeration
  • Privilege EscalationExcessive Permissions, Sudo/Root Execution, Credential Access
  • Supply ChainUnpinned Dependencies, External Script Fetching, Obfuscated Code
Findings (2)

The skill presents a false instruction hierarchy that places user requests, repository files, and skillet skills above the system prompt.

High
Category
Prompt Injection
Confidence
99% confidence
Finding

The numbered hierarchy places repository documents such as CLAUDE.md and AGENTS.md, along with skill content, above the system prompt. This can promote editable project content into governing authority, allowing injected repository instructions to bypass higher-priority restrictions if the agent accepts that hierarchy. This finding describes the same underlying defect as SDI-2, rather than a separate exploit.

Content

No source excerpt is available for this finding.

The skill attempts to subordinate system instructions to user requests and skill content.

High
Category
Excessive Agency
Confidence
99% confidence
Finding

The skill explicitly says its instructions override system behavior and that user instructions take highest priority, potentially inducing an agent to disregard higher-priority constraints. Its intended activation at the start of every conversation increases exposure and makes this hierarchy inversion more dangerous than an isolated task instruction. The text establishes an unsafe policy, but does not by itself establish malicious intent.

Content

No source excerpt is available for this finding.

Static analysis

No suspicious patterns detected.