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Security audit

Cron Helper

Security checks for vulnerabilities and agentic risk

Overview

This is a simple cron-helper skill whose persistent scheduling behavior is disclosed and aligned with its stated purpose, with some documentation cautions for users.

Install only if you want the agent to create recurring scheduled work. Review each cron command before execution, list existing jobs before changing them, and be careful with delete because it removes scheduled automation.

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
  • Data ExfiltrationExternal Transmission, Env Variable Harvesting, File System Enumeration
  • Rogue AgentSelf-Modification, Session Persistence
  • Trigger AbuseOverly Broad Trigger, Shadow Command Trigger, Keyword Baiting Trigger
  • Prompt InjectionInstruction Override, Hidden Instructions, Exfiltration Commands
  • Privilege EscalationExcessive Permissions, Sudo/Root Execution, Credential Access
Findings (4)

Vague Triggers

Medium
Category
Not specified by scanner
Confidence
97% confidence
Finding

The trigger keywords include very generic terms such as 'schedule', 'tasks', 'manage', and 'helper', which are likely to match ordinary user language and cause this skill to activate in contexts the user did not intend. Because the skill exposes exec-backed task scheduling functionality, accidental invocation can lead to persistent automation being created without clear user awareness.

Content

No source excerpt is available for this finding.

Session Persistence

Medium
Category
Rogue Agent
Confidence
80% confidence
Finding

The skill is explicitly designed to create recurring tasks, which introduces session persistence and durable side effects beyond the immediate interaction. Persistence is contextually expected for a cron helper, but it still creates security and operational risk if users are not clearly informed, if scheduled actions run unattended, or if accidental activation occurs.

Content

Scanner excerpt · SKILL.md (reported line 41)May include surrounding context.

md
# Cron Helper

Schedule recurring tasks for your AI agent without wrestling cron syntax.

## Features

Missing User Warnings

Medium
Category
Not specified by scanner
Confidence
93% confidence
Finding

The documentation instructs users how to create, pause, resume, and delete recurring tasks, but it does not warn that these actions are persistent and can alter future agent behavior or remove existing scheduled work. In a skill with exec capability, missing safety guidance increases the chance of unintended durable changes, disruptive deletions, or silent background task creation.

Content

No source excerpt is available for this finding.

Natural-Language Policy Violations

Low
Category
Not specified by scanner
Confidence
91% confidence
Finding

The file presents a substantial portion of the description in Chinese while the rest of the document is in English, with no indication that the user opted into Chinese or that the skill is region-specific. This can violate language/locale expectations by effectively forcing part of the experience into a specific language.

Content

No source excerpt is available for this finding.