nemu_create_jni_handle
Create a mock JNI object handle pre-populated with controlled data. Use BEFORE calling JNI functions to seed the handle table so that GetStringUTFChars / GetObjectArrayElement / GetIntField return expected values. Returns the handle id to pass as an argument to nemu_call_address or nemu_call_symbol.
This record as markdown: /tools/io-github-vmoranv-jshookmcp/nemu-create-jni-handle.md
What nemu_create_jni_handle does on Jshookmcp
AI agents invoke nemu_create_jni_handle to trigger actions in Jshookmcp. 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.
Why nemu_create_jni_handle is rated High
Seeds JNI handle table with controlled data to manipulate native function execution behavior.
From the tool's definition Create a mock JNI object handle pre-populated with controlled data
Attacks that exploit this kind of access
The rule that runs nemu_create_jni_handle safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Jshookmcp, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For nemu_create_jni_handle, this is the rule to start with:
nemu_create_jni_handle 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.
The button opens the PolicyLayer dashboard: create your workspace, connect Jshookmcp, apply this rule, and every nemu_create_jni_handle call is checked against it from then on.
Questions about nemu_create_jni_handle
Create a mock JNI object handle pre-populated with controlled data. Use BEFORE calling JNI functions to seed the handle table so that GetStringUTFChars / GetObjectArrayElement / GetIntField return expected values. Returns the handle id to pass as an argument to nemu_call_address or nemu_call_symbol. It is categorised as a Execute tool in the Jshookmcp MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the Jshook MCP server in PolicyLayer and add a rule for nemu_create_jni_handle: 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 Jshookmcp. Nothing to install.
nemu_create_jni_handle 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 nemu_create_jni_handle 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 nemu_create_jni_handle. 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.
nemu_create_jni_handle is provided by the Jshook MCP server (@jshookmcp/jshook). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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