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Task: Node.js Express app with flatnest and happy-dom. Solution: Prototype pollution via circular reference bypass in flatnest to enable JavaScript in happy-dom, then VM escape via this.constructor.constructor to access process.binding(fs) for file reading.

$ ls tags/ techniques/

nodejs express prototype-pollution happy-dom vm-escape flatnest circular-reference node-binding

prototype_pollution_via_circular_referencevm_escapeprocess_binding_fs

Analysis

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$ python3 exploit.py --target 192.168.1.1 --port 8080
[*] Connecting to target...
[+] Shell obtained!

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