Back to skill

Security audit

YoPlanning

Security checks for vulnerabilities and agentic risk

Overview

The YoPlanning reader fits its purpose, but setup directs the agent to run an unverified remote installer without clear user approval.

Review the setup behavior before installing. Install and verify the CLI separately instead of letting a missing-command error trigger downloaded code execution, and check which other agent skills it installs or updates. Connecting YoPlanning authorizes OOMOL to use that account's API key. The actual installer contents remain unverified.

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
  • Supply ChainUnpinned Dependencies, External Script Fetching, Obfuscated Code
  • Excessive AgencyUnrestricted Tool Access, Autonomous Decision Making, Scope Creep
  • Output HandlingUnvalidated Output Injection, Cross-Context Output, Unbounded Output
  • MCP Tool PoisoningHidden Instructions, Unicode Deception, Parameter Description Injection
  • Prompt InjectionInstruction Override, Hidden Instructions, Exfiltration Commands
Findings (4)

Description-Behavior Mismatch

High
Category
MCP Tool Poisoning
Confidence
96% confidence
Finding

The supplied command installs software through a remote shell script rather than searching or reading YoPlanning data. Although installation can be a supporting implementation detail, the supplied code establishes no relationship between this installer and the declared YoPlanning functionality. The script's contents are not supplied, so its exact system changes cannot be determined.

Content

No source excerpt is available for this finding.

External Script Fetching

High
Category
Supply Chain
Confidence
97% confidence
Finding

Piping an unpinned HTTPS response directly into Bash executes whatever the installation endpoint supplies with the agent process's local privileges; the PowerShell alternative has the same trust problem. Compromise of the endpoint or release pipeline could therefore enable local data theft or modification, although installation is conditional and may be blocked by the declared tool restriction.

Content

Scanner excerpt · SKILL.md (reported line 60)May include surrounding context.

The setup fallback instructs the agent to execute a downloaded installer without warning about local system changes.

Medium
Category
Output Handling
Confidence
91% confidence
Finding

On a missing-command error, the skill directs installation without first obtaining approval for executing downloaded code or changing the local environment. The error-triggered fallback limits exposure, and strict enforcement of the declared oo-only Bash permission could block installation, but the setup instructions themselves lack an authorization boundary.

Content

No source excerpt is available for this finding.

Autonomous Decision Making

Medium
Category
Excessive Agency
Confidence
80% confidence
Finding

Skill enables autonomous high-impact decisions without human-in-the-loop verification. Critical operations (destructive commands, financial transactions, data deletion) should require explicit user confirmation.

Content

Scanner excerpt · SKILL.md (reported line 81)May include surrounding context.

md
- **`OOMOL_INSUFFICIENT_CREDIT`** — OOMOL billing stop. Recharge at `https://console.oomol.com/billing/token-recharge` before retrying.

- **HTTP 402 without `OOMOL_INSUFFICIENT_CREDIT`** — the third-party account itself has no active plan or credit. Report the provider error message as is; do not ask the user to recharge OOMOL.

## Resources