Launch Arjun (HTTP parameter discovery tool) to find hidden HTTP parameters.
AI agents invoke launch_arjun_scan to trigger actions in pentestMCP. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.
This tool executes an active security scanner against external targets. While ostensibly for legitimate penetration testing, an AI agent with this capability could launch reconnaissance attacks against unintended targets or targets without authorization. The tool's effects depend entirely on what target and parameters are provided by the agent.
From the tool's definition Tool launches Arjun, which is an active HTTP parameter discovery scanner that sends requests to target servers.
Documented attack patterns abuse exactly the kind of access launch_arjun_scan gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and pentestMCP, and nothing reaches the server without passing your rules. This is the rule we recommend for launch_arjun_scan:
{
"version": "1",
"default": "deny",
"tools": {
"launch_arjun_scan": {
"limits": [
{
"counter": "launch_arjun_scan_rate",
"window": "minute",
"max": 10,
"scope": "grant"
}
]
}
}
}launch_arjun_scan 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.
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Launch Arjun (HTTP parameter discovery tool) to find hidden HTTP parameters. It is categorised as a Execute tool in the pentestMCP MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the pentest MCP server in PolicyLayer and add a rule for launch_arjun_scan: 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 pentestMCP. Nothing to install.
launch_arjun_scan is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the launch_arjun_scan 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.
Set action: deny in the PolicyLayer policy for launch_arjun_scan. 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.
launch_arjun_scan is provided by the pentest MCP server (ramkansal/pentestmcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 36 pentestMCP tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
36 pentestMCP tools catalogued and risk-classified — across an index of 42,500+ MCP servers.