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Ntobjmanager

@lupingqaqMCP server Β· External

Stateful Windows RPC attack-surface research for AI agents: 22 tools on NtObjectManager.

Penetration testingv1.0.0MITPython
Freeno charge per call

Runs on your machine from its package; the steps are below.

What it does

  1. Reads
  2. Writes
  3. High impact

Not assessed yet.

What it costs

Free

Odel charges nothing per call. The publisher may charge for its own service.

Runs locally

This server runs on your machine over stdio, but its source registry didn't list a distribution package. Check the source repository for setup instructions.

README6 min read

πŸ›°οΈ NtObjectManager-MCP

Stateful Windows RPC Research MCP β€” 2024–2026 CVE methodologies as one-click tools

Python License PowerShell MCP

🌐 δΈ­ζ–‡η‰ˆ


What is NtObjectManager-MCP?

A Model Context Protocol server that gives an AI agent live, stateful access to Windows RPC attack-surface research, built on James Forshaw's NtObjectManager (NtCoreLib).

Three things a generic PowerShell MCP cannot do β€” and the reason this exists:

  1. Stateful RPC connections β€” a persistent PowerShell engine keeps parsed RpcServer objects and connected RPC clients alive across tool calls: rpc_connect once, rpc_call many times (auth handshakes, context-handle chains, session variables survive).
  2. CVE methodology as fixed tools β€” the standard hunting workflows from 2024–2026 public research are one-click, not prompt-engineering.
  3. Stateful execution inside a lab VM β€” the same one-engine principle applied in the guest: rpc_vm_exec keeps variables and connected RPC clients alive across calls through a single persistent guest runspace, never a fresh shell per call (the vmrun fallback is reported as stateful: false).
β”Œβ”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”
β”‚  AI Agent (Claude Code / OpenCode / any MCP client)                β”‚
β”‚      β”‚  MCP (stdio, 24 tools)                                      β”‚
β”‚      β–Ό                                                             β”‚
β”‚  server.py ── snippets.py (PS templates, @@TOKEN@@ + ps_str escape)β”‚
β”‚      β”‚                                                             β”‚
β”‚      β–Ό                                                             β”‚
β”‚  ps_engine.py ── persistent powershell.exe (base64 + __MCP_DONE__) β”‚
β”‚      β”‚            state: $RPCMCP = @{ Servers; Clients; vars }     β”‚
β”‚      β–Ό                                                             β”‚
β”‚  NtObjectManager / NtCoreLib  ──►  RPC runtime (ALPC / pipe / TCP) β”‚
β””β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”˜

Tool Matrix (24)

Core stateful pipeline

ToolPurpose
rpc_parse(file, symbol_path?)Parse a PE for RPC servers, cache (keys file_N)
rpc_state()Cached servers + live sessions
rpc_get_interface(key)Procedures, NDR params, context handles, strictness
rpc_query_endpoints(ifid?, search_binding?, find_alpc_port?)EPM query (local or remote)
rpc_running_servers(pid?/service?)Live process/service enumeration
rpc_connect(session, key, binding?, auth?)Generate + connect client (stateful)
rpc_methods(session)Signatures with opnum mapping
rpc_call(session, method, args_json, store_as?)Reflection invoke; {"__var__"} passes stored objects
rpc_disconnect(session)Drop session

VM lab bridge (stateful guest execution)

ToolPurpose
rpc_vm_exec(ps, timeout?, vm?)Run PowerShell inside a lab VM; state survives across calls (persistent guest runspace)
rpc_vm_start_listener(vm?)Deploy/start the persistent guest HTTP engine (vm_listener.ps1)

2024–2026 CVE methodology tools

ToolMethodology source
rpc_scan_context_handles(paths)Context-handle type confusion β€” CVE-2025-48815 pattern (whereisk0shl 2026)
rpc_inventory(paths?, limit?)Attack-surface inventory + EPM cross-check β€” MS-RPC-Fuzzer phase 1 (CVE-2025-26651)
rpc_fuzz(session, dry_run=True)Primitive-only default-value fuzzing with ok/denied/error classification β€” dry-run by default
rpc_find_hijackable()Unregistered interfaces of stopped services β€” EPM poisoning / RPC-Racer (CVE-2025-49760/59200/59230)
rpc_etw_unreachable(duration, trigger_script?)Clients calling dead servers β€” PhantomRPC (Kaspersky 2026), admin required
rpc_interface_security(key)ALPC SD / anonymous-ACE audit β€” MS-NRPC null session (SafeBreach/Securelist 2025)
rpc_decode_flags(flags)RpcServerRegisterIf3 flag bitmask decoding
rpc_format_client(key)Export generated C# client source (offline grep workflow)
rpc_new_struct(session, type, store_as)Build NDR complex types as session vars
rpc_alpc_squat(name, duration)ALPC port squat + connection capture (race validation primitive)
rpc_accessible_tasks()User-startable tasks (Dark-Elevator chain material, CVE-2026-66804 pattern)
rpc_vars / rpc_clear_cacheSession-variable and cache management (eviction cap 150)

Every tool call is appended to output/mcp_audit.log.

Field-Tested (real machine, full hunting round)

CandidateResult
srvsvc.dll 98716d03… flagged HIGHIdentified as XactSrv (XsOpenPrinter/XsClosePrinter/XsAddJob/XsScheduleJob) β€” single printer-handle type; live probe: non-admin connect OK but XsOpenPrinter β†’ ACCESS_DENIED (authorization gate works). Scanner false-positive mode documented
ssdpsrv.dll (CVE-2025-48815 original)All 20 context handles strict β€” patched state on current builds
51-module sweep31 findings, 6 HIGH, all "one producer β†’ many consumers"; NDR layer cannot prove multi-type handles (needs RE)
EPM hijack surface10 stopped services with unregistered interfaces (AppIDSvc, ClipSVC, dcsvc…)
Task chains44 user-startable SYSTEM tasks inventoried
VerdictNo confirmable exploitable vuln on the tested host β€” with per-step evidence

πŸš€ Quick Start

powershell
# 1) Prerequisites (one-time)
Install-Module NtObjectManager -Scope CurrentUser -Force
pip install -r requirements.txt            # mcp>=1.2.0 (1.x / 2.x compatible)

# 2) Verify β€” three suites, all green
python tests\smoke_test.py                 # 17 checks (live MCP stdio round-trip)
python tests\var_test.py                   # 10 checks (store_as / __var__ mechanics)
python tests\audit.py                      # 43 checks (edge cases, hostile paths, concurrency)

# 3) Run the server
python server.py                           # stdio MCP

Claude Code:

bash
claude mcp add ntobjectmanager-rpc -- python C:\path\to\ntobjmanager-mcp\server.py

Any MCP client (e.g. OpenCode opencode.json):

json
{
  "mcp": {
    "ntobjectmanager-rpc": {
      "type": "local",
      "command": ["python", "C:\\path\\to\\ntobjmanager-mcp\\server.py"],
      "enabled": true
    }
  }
}

Example: context-handle type confusion (CVE-2025-48815 pattern)

1. rpc_parse  C:\Windows\System32\target.dll  [symbol_path optional]
2. rpc_scan_context_handles ["C:\\Windows\\System32\\target.dll"]
3. rpc_get_interface target_0                 β†’ producer ([out] ctx) / consumer ([in] ctx) pairs
4. rpc_connect s1 target_0                    β†’ auto-discovers binding via EPM
5. rpc_methods s1                            β†’ opnum-mapped signatures
6. rpc_call s1 XsOpenPrinter-like args store_as="h"   β†’ keep the raw handle object
7. rpc_call s1 XsClosePrinter-like [{"__var__":"h"}] β†’ feed it to the other type

store_as / {"__var__"} is the core chain primitive: RPC return objects flow between calls without serialization round-trips, which is exactly what producer→consumer handle-confusion testing needs.

πŸ“ Project Structure

ntobjmanager-mcp/
β”œβ”€β”€ server.py            # 24 MCP tools + audit logging wrapper
β”œβ”€β”€ snippets.py          # PowerShell templates (@@TOKEN@@ render + ps_str escaping)
β”œβ”€β”€ ps_engine.py         # Persistent engine: base64 cmds + __MCP_DONE__ markers, timeouts
β”œβ”€β”€ wrapper.ps1          # PS-side loop (state lives in $RPCMCP)
β”œβ”€β”€ vm_listener.ps1      # Persistent guest HTTP bridge (stateful VM exec)
β”œβ”€β”€ tests/
β”‚   β”œβ”€β”€ smoke_test.py    # 17 checks β€” live stdio end-to-end
β”‚   β”œβ”€β”€ var_test.py      # 10 checks β€” store_as/__var__ object passing
β”‚   β”œβ”€β”€ audit.py         # 43 checks β€” hostile inputs, concurrency, engine kill/restart
β”‚   β”œβ”€β”€ hunt.py          # Full dogfood hunting round (safe policy)
β”‚   β”œβ”€β”€ hunt2_static.py  # Deep-dive: symbols + producer/consumer map
β”‚   β”œβ”€β”€ hunt2_wide.py    # 51-module sweep
β”‚   └── hunt2_probe.py   # Safe runtime probes (exposure / task cross-ref)
β”œβ”€β”€ ARCHITECTURE.md      # Engine protocol + design decisions
β”œβ”€β”€ CHANGELOG.md         # Decision history (R1–R13)
β”œβ”€β”€ SECURITY.md          # Authorized-use policy + MSRC disclosure
β”œβ”€β”€ CONTRIBUTING.md      # Development invariants
└── LICENSE              # MIT

πŸ›‘οΈ Honest Capability Boundaries

ClaimStatus
Stateful clients across tool callsYes β€” persistent engine + $RPCMCP
Stateful execution inside a lab VMYes β€” one persistent guest runspace (rpc_vm_exec); the vmrun fallback is stateless
Context-handle chaining (producer β†’ consumer)Yes β€” store_as / __var__ raw-object passing
Auto-confirm type confusionNo β€” NDR cannot prove distinct handle types; verify via RE (see XactSrv case)
Full rogue-RPC hostingNo β€” NtObjectManager 2.0.1 ships no server builder; rpc_alpc_squat covers race-capture only
ETW tracing / ALPC SDDLRequires admin (logman / SeDebugPrivilege)
Symbol-resolved procedure namesEnvironment-dependent (symsrv chain); heuristic fallback names otherwise
Runs anywhere but Windows PS 5.1Not yet (pwsh 7 untested)

πŸ“– Documentation

  • ARCHITECTURE.md β€” engine protocol, state model, design decisions
  • CHANGELOG.md β€” R1–R13 decision history incl. two PS 5.1 marshaling bugs
  • SECURITY.md β€” authorized use, VM isolation, MSRC disclosure
  • CONTRIBUTING.md β€” development invariants and test requirements

⚠️ Disclaimer

For lawful security research, education, and authorized testing only. rpc_call invokes real RPC methods and can crash services β€” run it against an isolated VM, never a production or daily-driver host. Vulnerabilities found through this tool must follow responsible disclosure (MSRC).

πŸ“„ License

MIT β€” Copyright (c) 2026 ntobjmanager-mcp Contributors

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