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Security audit

Amazon API

Security checks for vulnerabilities and agentic risk

Overview

The skill appears to perform the advertised Amazon API lookups, but its documented helper can expose the JustOneAPI token through command-line arguments and request URLs.

Review before installing if your JustOneAPI token has spending, quota, or account impact. Prefer running it only in trusted environments, avoid logging full commands or URLs, and rotate the token if it may have appeared in logs or process telemetry.

Vulnerability Patterns
  • 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
  • Embedded Malicious CodeShips malicious scripts inside the skill and executes them locally
Findings (1)

T09 · Insecure Skill Coding Practices

Warning
Location
bin/run.mjs:346
Finding

API Credential Exposed Through URL Query String and Command-Line Arguments

Content
View full analysis
parameter.name === "token"); if (!tokenParam || params.token !== undefined) { return; } if (!cliToken) { fail("--token is required for this operation.", { operationId: operation.operationId, }); } params.token = cliToken; } ``` ```js function applyQueryParams(operation, params, url) { for (const parameter of operation.parameters.filter((item) => item.location === "query")) { const value = params[parameter.name]; if (value === undefined) { continue; } appendValue(url.searchParams, parameter.name, value); } } function appendValue(searchParams, name, value) { if (Array.isArray(value)) { for (const item of value) { appendValue(searchParams, name, item); } return; } if (value && typeof value === "object") { searchParams.append(name, JSON.stringify(value)); return; } searchParams.append(name, String(value)); } ``` ### Tec ...[truncated 2308 chars]
Remediation
View remediation
Vulnerability Patterns
  • Data ExfiltrationExternal Transmission, Env Variable Harvesting, File System Enumeration
  • System Prompt LeakageDirect Leakage, Indirect Extraction, Tool-Based Exfiltration
  • MCP Least PrivilegeUnderdeclared Capability, Wildcard Permission, Missing Permission Declaration
  • MCP Tool PoisoningHidden Instructions, Unicode Deception, Parameter Description Injection
  • Prompt InjectionInstruction Override, Hidden Instructions, Exfiltration Commands
Findings (7)

Direct Prompt Extraction

High
Category
System Prompt Leakage
Confidence
85% confidence
Finding

Skill contains instructions that could directly expose system prompts, internal rules, or hidden instructions to users or external parties.

Content

Scanner excerpt · SKILL.md (reported line 54)May include surrounding context.

md
- Get a token from [Just One API Dashboard](https://dashboard.justoneapi.com/en/login?utm_source=clawhub.ai&utm_medium=referral&utm_campaign=justoneapi_amazon&utm_content=project_link).
- Authentication details: [Just One API Usage Guide](https://docs.justoneapi.com/en/?utm_source=clawhub.ai&utm_medium=referral&utm_campaign=justoneapi_amazon&utm_content=project_link).

## Output Rules

- Start with a plain-language answer tied to the Amazon task the user asked for.
- Include the most decision-relevant fields from the selected endpoint before dumping raw JSON.

Undeclared Tool Scope

Medium
Category
MCP Least Privilege
Confidence
93% confidence
Finding

The skill invokes a Node helper that performs authenticated external API requests, but the manifest does not declare an explicit tool scope such as allowed network access or permissions. This weakens policy enforcement and reviewability because the skill's effective capabilities are broader than what its top-level declaration communicates, increasing the chance of unintended network use or over-privileged execution.

Content

No source excerpt is available for this finding.

Missing User Warnings

Medium
Category
Not specified by scanner
Confidence
97% confidence
Finding

The skill accepts the API token via a CLI argument and then injects it into a query parameter, causing the secret to appear in the full request URL. Secrets in command-line arguments can be exposed through shell history and process listings, and secrets in URLs are commonly captured by logs, proxies, monitoring tools, and error telemetry, increasing the chance of credential leakage.

Content

No source excerpt is available for this finding.

Missing User Warnings

Medium
Category
Not specified by scanner
Confidence
97% confidence
Finding

The API documentation requires an authentication token in the query string, which is commonly logged by browsers, proxies, server access logs, analytics tools, and referrer headers. Exposing credentials this way increases the chance of token leakage and unauthorized API use, especially in an integration skill where users may copy, paste, or troubleshoot requests through multiple systems.

Content

No source excerpt is available for this finding.

Description-Behavior Mismatch

Medium
Category
Not specified by scanner
Confidence
97% confidence
Finding

The manifest says the skill supports product details, product top reviews, and best sellers across 4 operations, but this file defines a fourth operation, getProductsByCategoryV1, that is not mentioned in the manifest description. That creates a semantic mismatch between the advertised scope and the implemented API surface.

Content

No source excerpt is available for this finding.

Description-Behavior Mismatch

Low
Category
Not specified by scanner
Confidence
97% confidence
Finding

The manifest description says the skill covers product Details, product Top Reviews, and best Sellers across 4 operations, but the listed operations also include getProductsByCategoryV1. That means the code exposes an additional Amazon category-product retrieval capability not disclosed in the top-level description.

Content

No source excerpt is available for this finding.

Description-Behavior Mismatch

Low
Category
Not specified by scanner
Confidence
98% confidence
Finding

The manifest description at L003 limits the advertised scope to product Details, product Top Reviews, and best Sellers across 4 operations. However, the operations list also includes 'Products By Category' at L088-L170, which is a distinct capability not mentioned in the description.

Content

No source excerpt is available for this finding.