webhard

MSN Revive

srdnlen

Task: MSN Messenger clone with nginx/Node.js/Flask architecture, flag in bot chat session, export endpoint restricted to localhost. Solution: Content-Length desync via binary MSNP2P protocol header manipulation with keepAlive connection poisoning to smuggle request bypassing localhost restriction.

$ ls tags/ techniques/

flask nodejs binary_protocol express http_request_smuggling access_control_bypass reverse_proxy content_length_desync keepalive msnp2p

cl_desync_via_binary_protocol_headerhttp_request_smuggling_keepalivegateway_localhost_restriction_bypassbinary_header_content_length_manipulation

Analysis

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

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