js_list

THE RISK

Low Risk

Why js_list needs a policy

This tool lists JavaScript sources without modifying, executing, or deleting them. It is a simple enumeration that returns information about existing registered JS sources in Burp Suite's context. The action is read-only and poses minimal security risk to the system.

From the tool's definition Tool name 'js_list' and description 'List all registered JS sources' indicate a query/retrieval operation with no side effects.

Documented attack patterns abuse exactly the kind of access js_list gives an agent:

POLICY

How to control js_list

PolicyLayer is an MCP gateway — it sits between your AI agents and Burp Mcp Plus, and nothing reaches the server without passing your rules. This is the rule we recommend for js_list:

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "js_list": {}
  }
}

js_list is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.

Create a free account and register Burp Mcp Plus — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

CAP THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More Burp Mcp Plus tools

Execute intruder_from_history intruder_from_history Execute repeater_from_history repeater_from_history Execute repeater_from_template repeater_from_template Execute collaborator_generate Generate one or more Burp Collaborator payloads. Execute dedup_to_repeater Send a dedup entry to Burp Repeater, with optional structured overrides. Execute send_request send_request Read sitemap Build a sitemap from Burp proxy history (no upstream Target tool exists). Read collaborator_check Poll Burp Collaborator for received interactions.

All 20 Burp Mcp Plus tools →

Read tools on other servers

M-Team MCP Server get_torrent_detail YouTube MCP Server search_channel Android Forensics ADB MCP Server parse_browser_history 0xarchive web3_challenge

Go deeper

The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Data exfiltration → How read access becomes an exfiltration channel when chained with untrusted content.
MCP token cost → What connecting this server costs in context-window tokens on every request.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about js_list

What does the js_list tool do? +

List all registered JS sources. It is categorised as a Read tool in the Burp Mcp Plus MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on js_list? +

Register the Burp Mcp Plus MCP server in PolicyLayer and add a rule for js_list: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Burp Mcp Plus. Nothing to install.

What risk level is js_list? +

js_list is a Read tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit js_list? +

Yes. Add a rate_limit block to the js_list rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block js_list completely? +

Set action: deny in the PolicyLayer policy for js_list. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides js_list? +

js_list is provided by the Burp Mcp Plus MCP server (titaniumtushar/burp-mcp-plus). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Burp Mcp Plus tool call.

Start from Burp Mcp Plus, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →