AI agents invoke fierce_scan to trigger actions in Kali Security MCP. 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.
Fierce is a DNS reconnaissance tool that actively queries DNS servers to enumerate subdomains, hosts, and network ranges. It triggers external network operations against target infrastructure. In the context of a penetration testing server with tools like 'ad_full_attack' and 'adaptive_network_penetration', this tool is used for active reconnaissance which can expose attack surface information.
From the tool's definition 使用 Fierce 执行 DNS 侦察 (Uses Fierce to perform DNS reconnaissance)
Documented attack patterns abuse exactly the kind of access fierce_scan gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Kali Security MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for fierce_scan:
{
"version": "1",
"default": "deny",
"tools": {
"fierce_scan": {
"limits": [
{
"counter": "fierce_scan_rate",
"window": "minute",
"max": 10,
"scope": "grant"
}
]
}
}
}fierce_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.
Free to start. No card required.
使用 Fierce 执行 DNS 侦察。. It is categorised as a Execute tool in the Kali Security MCP MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the Kali Security MCP server in PolicyLayer and add a rule for fierce_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 Kali Security MCP. Nothing to install.
fierce_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 fierce_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 fierce_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.
fierce_scan is provided by the Kali Security MCP server (seac-25/kali-security-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 249 Kali Security MCP tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
249 Kali Security MCP tools catalogued and risk-classified — across an index of 42,500+ MCP servers.