stop_xsser_gui

THE RISK

High Risk

Why stop_xsser_gui needs a policy

Process termination is an Execute action because it directly triggers a system operation (kill/terminate) whose effect depends on the supplied PID argument. While not destructive to data per se, it can disrupt running operations and affects system state.

From the tool's definition The tool 'terminates a background XSSer GUI process using its PID' - this performs process termination, a system-level operation that executes an external command with side effects.

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

POLICY

How to control stop_xsser_gui

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

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "stop_xsser_gui": {
      "limits": [
        {
          "counter": "stop_xsser_gui_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

stop_xsser_gui stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

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

RATE-LIMIT THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More Pentester-MCP tools

Execute dnscat_client dnscat_client Execute execute_weevely_module execute_weevely_module Execute identify_hash identify_hash Execute john_prepare john_prepare Execute launch_xsser_gui Launches the graphical user interface (GTK) for XSSer. Execute objection_explore objection_explore Execute run_403bypasser run_403bypasser Execute run_addcomputer run_addcomputer

All 337 Pentester-MCP tools →

Execute tools on other servers

Android Forensics ADB MCP Server adb_shell_command EMBA-MCP run_emba_scan Frida Game Hacking MCP remove_breakpoint Procmon request_elevation

Go deeper

Govern code and CI agents → Branch allowlists, approval on merges, and rate caps on the build and pipeline tools agents trigger.
High-risk tools in Pentester-MCP → Every high-risk tool this server exposes, in one view.
All high-risk MCP tools → Every high-risk tool across the catalogue, and the policy pattern that contains them.
The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Agent sandbox → Bounding what an agent can execute and where the boundary should sit.
Least privilege for MCP → Granting agents the minimum tool surface the task needs.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →
PolicyLayer vs alternatives → How deterministic, per-call MCP policy compares with gateways, identity layers, and authorisation platforms.

FAQ

Questions about stop_xsser_gui

What does the stop_xsser_gui tool do? +

Terminates a background XSSer GUI process using its PID. It is categorised as a Execute tool in the Pentester-MCP MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on stop_xsser_gui? +

Register the Pentester- MCP server in PolicyLayer and add a rule for stop_xsser_gui: 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 Pentester-MCP. Nothing to install.

What risk level is stop_xsser_gui? +

stop_xsser_gui is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit stop_xsser_gui? +

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

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

stop_xsser_gui is provided by the Pentester- MCP server (halilkirazkaya/pentester-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Pentester-MCP tool call.

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

CHECK YOUR STACK →