Quick search focused on harvesting email addresses from a domain.
AI agents call theharvester_emails to retrieve information from theHarvester MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
Email harvesting via OSINT tools like theHarvester is fundamentally a Read operation—it queries public sources (DNS records, search engines, etc.) and returns results with no side effects on target systems. Severity is medium because harvested email lists can facilitate follow-on attacks (phishing, spam, credential stuffing), but the tool itself performs passive reconnaissance only.
From the tool's definition Tool is named 'theharvester_emails' and described as performing 'Quick search focused on harvesting email addresses from a domain.' This is a query/retrieval operation that passively gathers publicly available email addresses without modifying, deleting, or…
Attacks that exploit this kind of access
Quick search focused on harvesting email addresses from a domain. It is categorised as a Read tool in the theHarvester MCP Server MCP Server, which means it retrieves data without modifying state.
Register the theHarvester MCP Server MCP server in PolicyLayer and add a rule for theharvester_emails: 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 theHarvester MCP Server. Nothing to install.
theharvester_emails is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the theharvester_emails 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 theharvester_emails. 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.
theharvester_emails is provided by the theHarvester MCP Server MCP server (schwarztim/sec-theharvester-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
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