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Security audit

Ably

Security checks for vulnerabilities and agentic risk

Overview

This skill asks before changing Ably data, but its setup can run downloaded software without asking first.

Review and approve CLI installation separately, preferably using a fixed release with verified integrity. Check whether it installs or updates other agent skills. Limit the connected Ably account's permissions and retain the skill's write/delete confirmations. Remote installer and service behavior were not verified; 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
97% confidence
Finding

The supplied chunk performs remote script execution for an Oomol CLI installer, not Ably data operations. Nothing in the supplied material establishes this installation as a supporting dependency for the declared purpose. The downloaded script's contents and any further effects are unknown.

Content

No source excerpt is available for this finding.

Description-Behavior Mismatch

High
Category
MCP Tool Poisoning
Confidence
86% confidence
Finding

The supplied code only runs a login command; it does not identify Ably or implement any Ably data operations. Authentication could be a supporting implementation detail if its connection to Ably were established, but the supplied chunk provides no such connection.

Content

No source excerpt is available for this finding.

External Script Fetching

High
Category
Supply Chain
Confidence
98% confidence
Finding

Piping a live HTTPS download directly into Bash executes mutable remote code with the invoking user's privileges, without a pinned version or independent integrity verification. Compromise of the installer distribution path could expose local files and credentials or enable persistent host modification; the legitimate OOMOL dependency and setup-only trigger do not eliminate this risk. The PowerShell installation example has the same underlying issue.

Content

Scanner excerpt · SKILL.md (reported line 65)May include surrounding context.

The setup workflow executes downloaded installation scripts without warning the user about remote code execution or system changes.

Medium
Category
Output Handling
Confidence
92% confidence
Finding

The missing-CLI fallback instructs the agent to execute a remote installer without first explaining its system changes or requesting installation approval. A failed Ably request can therefore escalate into local software installation; the setup-only condition limits exposure, but does not establish informed authorization.

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 86)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