nemu_gdbserver
GDB Remote Serial Protocol (RSP) TCP server. Starts a real TCP server on host:port that GDB clients can connect to. Provides full register read/write, memory read/write, step, continue, software breakpoints (Z0/z0), vCont extended step/continue, qXfer target description, thread listing, and featu...
This record as markdown: /tools/io-github-vmoranv-jshookmcp/nemu-gdbserver.md
What nemu_gdbserver does on Jshookmcp
AI agents invoke nemu_gdbserver 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_gdbserver is rated High
Enables arbitrary code execution and memory manipulation through debugger protocol access to emulator.
From the tool's definition GDB Remote Serial Protocol server, register read/write, memory read/write, step, continue, breakpoints.
Attacks that exploit this kind of access
The rule that runs nemu_gdbserver 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_gdbserver, this is the rule to start with:
nemu_gdbserver 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_gdbserver call is checked against it from then on.
Questions about nemu_gdbserver
GDB Remote Serial Protocol (RSP) TCP server. Starts a real TCP server on host:port that GDB clients can connect to. Provides full register read/write, memory read/write, step, continue, software breakpoints (Z0/z0), vCont extended step/continue, qXfer target description, thread listing, and feature negotiation (qSupported). The server dispatches commands to the nemu emulator session in real-time. Packet format: $data#checksum (RFC 5.1 GDB Remote Serial Protocol). Actions: start (launch TCP server), stop (shut down), status (server + clients). Note: step/continue are simulated (PC += 4, immediate SIGTRAP); real execution control requires CpuEngine.runUntilBreakpoint() which is not yet exposed. 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_gdbserver: 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_gdbserver 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_gdbserver 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_gdbserver. 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_gdbserver 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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