get_storage

THE RISK

Low Risk

Why get_storage needs a policy

This tool retrieves sensitive client-side storage without modifying it. While it is fundamentally a Read operation, the severity is high because browser storage often contains authentication tokens, session identifiers, personal data, and other sensitive information that could be exfiltrated by a compromised agent.

From the tool's definition Tool description states 'Gets browser storage data including cookies, localStorage, and sessionStorage' — the verb 'Gets' indicates data retrieval with no modification. Cookies, localStorage, and sessionStorage are read-only data access operations.

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

POLICY

How to control get_storage

PolicyLayer is an MCP gateway — it sits between your AI agents and JS Reverse Strong MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for get_storage:

policy.json

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

get_storage 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 JS Reverse Strong MCP — 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 JS Reverse Strong MCP tools

Destructive delete_session_state Delete one in-memory session snapshot by sessionId. Destructive remove_hook Remove a hook by id. Execute evaluate_on_callframe Evaluates a JavaScript expression in the context of a specific call frame while paused. Th Execute inject_preload_script Register a JavaScript snippet that will run on future document loads before page scripts e Execute navigate_page Navigates the currently selected page to a URL, or performs back/forward/reload navigation Execute new_page Creates a new page and navigates to the specified URL. Waits for DOMContentLoaded event (n Execute stop_monitor Stops an event monitor. Execute wait_for_element Wait for selector to appear.

All 85 JS Reverse Strong MCP 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 get_storage

What does the get_storage tool do? +

Gets browser storage data including cookies, localStorage, and sessionStorage. It is categorised as a Read tool in the JS Reverse Strong MCP MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on get_storage? +

Register the JS Reverse Strong MCP server in PolicyLayer and add a rule for get_storage: 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 JS Reverse Strong MCP. Nothing to install.

What risk level is get_storage? +

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

Can I rate-limit get_storage? +

Yes. Add a rate_limit block to the get_storage 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 get_storage completely? +

Set action: deny in the PolicyLayer policy for get_storage. 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 get_storage? +

get_storage is provided by the JS Reverse Strong MCP server (lwjjike/jsreverser-strong-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every JS Reverse Strong MCP tool call.

Start from JS Reverse Strong MCP, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →