Security audit

Marktplaats

Security checks for vulnerabilities and agentic risk

Overview

The skill is mostly a coherent Marktplaats search tool, but it exposes an overbroad detail fetcher that can request arbitrary URLs and documents an ambiguous npx command that may run an unrelated package.

Review this before installing. Use it only in environments where arbitrary outbound HTTP requests are acceptable, avoid passing untrusted values to --details or getListingDetails, and prefer the documented local/global install path over the README npx command unless the package name and version are explicitly pinned.

A.I.G

Vulnerability Patterns

Insecure DependenciesIntroduces malicious components through unsafe dependency sources
Insecure Skill Coding PracticesFinds exploitable flaws such as hardcoded secrets or command injection
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

Findings (2)

T09 · Insecure Skill Coding Practices

Error

Location: src/api.js:329
Finding: Arbitrary URL Fetch Enables Server-Side Request Forgery
Content: View full analysis
Remediation: View remediation

T08 · Insecure Dependencies

Warning

Location: README.md:8
Finding: Unpinned npx Instruction May Execute an Unrelated Registry Package
Content: View full analysis
Remediation: View remediation

SkillSpector

Vulnerability Patterns

Prompt InjectionInstruction Override, Hidden Instructions, Exfiltration Commands
Data ExfiltrationExternal Transmission, Env Variable Harvesting, File System Enumeration
Privilege EscalationExcessive Permissions, Sudo/Root Execution, Credential Access
Supply ChainUnpinned Dependencies, External Script Fetching, Obfuscated Code
Excessive AgencyUnrestricted Tool Access, Autonomous Decision Making, Scope Creep

Static analysis

No suspicious patterns detected.