7-echo.md

Port 7 - Echo

Table of Contents

• Enumeration
• Exploitation

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Enumeration

Quick Check (One-liner)

echo "test" | nc $rhost 7 && echo "Echo service responds"

Banner Grabbing

nc -vn $rhost 7

Nmap Scripts

nmap -sV -sC -p7 $rhost

UDP Echo

nmap -sU -p7 $rhost

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Exploitation

Testing Echo Service

# TCP
echo "test" | nc $rhost 7

# UDP
echo "test" | nc -u $rhost 7

Amplification Attack (DDoS)

Echo service can be used in amplification attacks

# Check if echo responds (potential amplification)
hping3 -c 1 --udp -p 7 $rhost

Network Reconnaissance

# Use echo to verify host is alive
for ip in $(seq 1 254); do
  echo "test" | nc -w1 192.168.1.$ip 7 2>/dev/null && echo "192.168.1.$ip is alive"
done

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References

• HackTricks - Echo