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Security audit

Microsoft To Do

Security checks for vulnerabilities and agentic risk

Overview

Task operations have clear approval safeguards, but setup can execute changing third-party code and install additional agent skills without separate approval.

Review the setup path before installing. Use a separately reviewed, verified CLI release and decide whether to allow its automatic agent-skill synchronization. Understand that OOMOL mediates access to your task data. Keep the skill's existing confirmation requirements for changes and deletion. The remote installers and hosted implementation were not verified.

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
95% confidence
Finding

The supplied chunk executes a remote installation script rather than interacting with Microsoft To Do. Dependency installation can be a supporting implementation detail, but no connection between this installer and the declared functionality is established here. The downloaded script's contents and further effects are not available for assessment.

Content

No source excerpt is available for this finding.

External Script Fetching

High
Category
Supply Chain
Confidence
98% confidence
Finding

Piping a live HTTPS response directly into bash executes remote code without inspecting it or verifying a pinned release or signature; the PowerShell alternative has the same issue. Compromise of the distribution endpoint or installer supply chain could result in arbitrary code execution with the invoking user's privileges, although the missing-CLI prerequisite limits when this path is reached.

Content

Scanner excerpt · SKILL.md (reported line 68)May include surrounding context.

The setup workflow executes downloaded installation scripts without warning about third-party code execution or local system changes.

Medium
Category
Output Handling
Confidence
93% confidence
Finding

The setup instructions direct the agent to execute downloaded scripts when the CLI is missing without explicitly obtaining approval for third-party code execution and local system changes. Although this is a legitimate dependency setup path, consent to manage cloud tasks does not necessarily authorize installing software on the local machine.

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 89)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