Back to skill

Security audit

Userlist

Security checks for vulnerabilities and agentic risk

Overview

Userlist changes require approval, but setup can execute unverified remote code and introduce undisclosed changes to other agent skills.

Review the setup behavior before enabling this skill. Prefer installing a reviewed CLI release yourself and confirm that OOMOL may process your Userlist data and credentials. To prevent startup changes to other agent skills, the publisher documents OO_SKILLS_SYNC_DISABLED=1; configure it before invoking the CLI. [CLI controls](https://github.com/oomol-lab/oo-cli/blob/main/docs/commands.md). Keep the existing approval requirement for data changes and messages. The remote installers could not be inspected; no malicious behavior was established.

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 (5)

Description-Behavior Mismatch

High
Category
MCP Tool Poisoning
Confidence
98% confidence
Finding

The supplied command installs software from Oomol rather than performing Userlist operations. Nothing in the supplied chunk establishes that this installer is a supporting dependency for Userlist, so its behavior is not adequately represented by the declared purpose. The downloaded script's further behavior cannot be determined from this chunk.

Content

No source excerpt is available for this finding.

Description-Behavior Mismatch

High
Category
MCP Tool Poisoning
Confidence
86% confidence
Finding

The supplied chunk's sole action is an authentication command, with no indication that oo is associated with Userlist. Authentication could be a supporting implementation detail if that connection were established, but the supplied content does not establish it and does not substantiate the declared Userlist purpose.

Content

No source excerpt is available for this finding.

External Script Fetching

High
Category
Supply Chain
Confidence
98% confidence
Finding

Piping an unpinned HTTPS response directly into bash executes whatever code the installer endpoint supplies with the invoking process's permissions. Compromise of that endpoint or its delivery pipeline could expose local files and credentials or enable persistent modifications; HTTPS alone does not establish release integrity, although execution is only prescribed when the CLI is missing.

Content

Scanner excerpt · SKILL.md (reported line 59)May include surrounding context.

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

Medium
Category
Output Handling
Confidence
94% confidence
Finding

The missing-CLI fallback directs installation through immediate execution of remotely fetched shell or PowerShell code without requiring informed approval for local system changes. Its conditional nature limits exposure, but the write-confirmation rules concern Userlist state and do not explicitly protect local installation.

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 80)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