List available mangling rules or test rules against words
AI agents call john_rules to retrieve information from John The Ripper without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves information about John the Ripper's available rules and allows testing rule syntax against sample words. It performs no destructive operations, executes no attacks, and has no side effects beyond returning informational data.
From the tool's definition Tool description states 'List available mangling rules or test rules against words' - this is a query/list operation with no data modification or execution of actual password cracking.
Attacks that exploit this kind of access
List available mangling rules or test rules against words. It is categorised as a Read tool in the John The Ripper MCP Server, which means it retrieves data without modifying state.
Register the John The Ripper MCP server in PolicyLayer and add a rule for john_rules: 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 John The Ripper. Nothing to install.
john_rules 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 john_rules 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 john_rules. 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.
john_rules is provided by the John The Ripper MCP server (schwarztim/sec-john-the-ripper-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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