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Security audit

Gumroad

Security checks for vulnerabilities and agentic risk

Overview

The Gumroad workflow has clear safeguards, but setup directs the agent to execute unverified remote installers without explicit user approval.

Review is warranted for automatic setup, not evidence of malicious intent. Install a verified CLI release yourself or explicitly approve installation after reviewing its local changes, including agent-skill synchronization. OOMOL mediates access to your Gumroad data; retain the required confirmations for refunds and other writes. Remote installer behavior remains 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
98% confidence
Finding

The supplied code executes an Oomol-hosted installer rather than performing the declared Gumroad data operations. Nothing in the chunk establishes this installation as a supporting dependency for Gumroad access. The downloaded script's contents and further effects cannot be determined from the supplied code.

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 a pinned version or independently verified integrity; the PowerShell alternative has the same weakness. Compromise of the installer distribution path could yield arbitrary execution with the invoking user's privileges, although the snippet alone does not establish malicious installer behavior or that execution occurred.

Content

Scanner excerpt · SKILL.md (reported line 63)May include surrounding context.

Fallback setup executes downloaded installation scripts without a system-integrity warning or user approval.

Medium
Category
Output Handling
Confidence
93% confidence
Finding

The fallback directs installation of executable software after a missing-command error without requiring approval for local system changes. Although limited to first-time setup and apparently intended to install a legitimate dependency, this expands a Gumroad task into local code execution and could expose accessible files and credentials if the installer is compromised.

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 84)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