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Security audit

Canvas Threejs

Security checks for vulnerabilities and agentic risk

Overview

This skill is a coherent browser graphics guidance package with no executable payload, persistence, credential access, or hidden high-impact behavior found.

Install this if you want agent guidance for browser graphics work. Expect it to influence rendering implementation choices and visual verification, but it does not appear to run code or access sensitive data on its own.

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
Vulnerability Patterns
  • Excessive AgencyUnrestricted Tool Access, Autonomous Decision Making, Scope Creep
  • Trigger AbuseOverly Broad Trigger, Shadow Command Trigger, Keyword Baiting Trigger
  • Prompt InjectionInstruction Override, Hidden Instructions, Exfiltration Commands
  • Data ExfiltrationExternal Transmission, Env Variable Harvesting, File System Enumeration
  • Privilege EscalationExcessive Permissions, Sudo/Root Execution, Credential Access
Findings (3)

Skill Enumeration

Medium
Category
Agent Snooping
Confidence
80% confidence
Finding

Skill enumerates or reads other installed skills. Access to other skills' SKILL.md files or the skills directory reveals prompt instructions, capabilities, and secrets that should be invisible to peer skills.

Content

Scanner excerpt · README.md (reported line 10)May include surrounding context.

md
- ID: `fec-canvas-threejs`
- Category: `implementation-capability`
- Version: `2.9.0`
- Source: `skills/fec-canvas-threejs/SKILL.md`

## Description

Vague Triggers

Medium
Category
Not specified by scanner
Confidence
94% confidence
Finding

The README's trigger guidance is broad enough to match many common frontend terms such as Canvas, WebGL, Shader, 3D, data visualization, and games without strong activation boundaries. In an agent-routing system, this can cause the skill to be invoked in situations outside its intended scope, increasing the chance of inappropriate code generation or review behavior and expanding the attack surface for prompt/skill selection abuse.

Content

No source excerpt is available for this finding.

Natural-Language Policy Violations

Medium
Category
Not specified by scanner
Confidence
91% confidence
Finding

The manifest text explicitly specifies 'Chinese triggers include Canvas, Three.js, WebGL, GLSL, Shader, 3D, data visualization, games,' which imposes a locale-specific trigger policy in natural language. The file does not indicate that language selection is optional or that equivalent triggers are offered by user choice.

Content

No source excerpt is available for this finding.

Static analysis

No suspicious patterns detected.