Port Scanner Result Analyzer
Parse and analyze port scan results to identify services and security risks.
About This Tool
The Port Scanner Result Analyzer parses and interprets output from network port scanners like nmap, providing security analysis and service identification. When you perform a port scan, the raw results can be difficult to interpret and may miss critical security implications. This tool automatically categorizes open ports, identifies running services, assesses security risks, and provides actionable recommendations to secure your infrastructure. Whether you're conducting security audits, hardening servers, or troubleshooting network connectivity, this analyzer helps you understand what services are exposed and which ones pose security risks.
How to Use
- Perform a port scan using nmap or similar tool (e.g., nmap -sV target-ip)
- Copy the scan results showing port numbers, states, and services
- Paste the results into the text area (supports nmap format: "22/tcp open ssh")
- Click "Analyze" to process the results
- Review the summary showing total, open, closed, and filtered ports
- Check open ports details with service identification and risk levels
- Review security recommendations specific to your exposed services
- Implement suggested security measures to reduce attack surface
Features
- Parses nmap and similar port scanner output formats
- Identifies services running on open ports
- Risk assessment (low, medium, high, critical) for each service
- Security recommendations based on exposed services
- Service categorization (web, database, remote access, etc.)
- Port statistics summary
- Color-coded risk indicators
- Database of 25+ common ports and services
- Actionable hardening suggestions
- Support for TCP and UDP protocols
Common Use Cases
- Security audits and penetration testing
- Server hardening and attack surface reduction
- Compliance checks (PCI-DSS, HIPAA, SOC 2)
- Troubleshooting network connectivity issues
- Validating firewall rules and network segmentation
- Incident response and forensic analysis
- Infrastructure documentation and inventory
- Vulnerability assessment and remediation planning
- Cloud security posture management
- DevSecOps integration and CI/CD security checks
Technical Details
Port scanning is a fundamental network reconnaissance technique used to discover open ports and services on target systems. Understanding scan results is crucial for security hardening.
Port States:
- Open: Port is accepting connections. Service is listening and reachable.
- TCP: SYN/ACK response received
- UDP: Application response or no ICMP unreachable
- Security implication: Potential attack vector
- Closed: Port is reachable but no service is listening.
- TCP: RST response received
- UDP: ICMP port unreachable received
- Security implication: Low risk, but reveals host is up
- Filtered: Firewall or packet filter blocking access.
- No response or ICMP unreachable (type 3, code 1/2/3/9/10/13)
- Cannot determine if port is open or closed
- Security implication: Firewall present (good for security)
- Open|Filtered: nmap cannot determine if open or filtered (UDP scans)
- Closed|Filtered: nmap cannot determine if closed or filtered (IPID idle scan)
Common Ports and Security Implications:
- Port 22 (SSH):
- Service: Secure Shell for remote administration
- Risk: Low if properly configured
- Hardening: Use key-based auth, disable root login, fail2ban, non-standard port
- Attacks: Brute force, credential stuffing
- Port 23 (Telnet):
- Service: Unencrypted remote access
- Risk: Critical - transmits passwords in cleartext
- Recommendation: Disable immediately, replace with SSH
- Never use on untrusted networks
- Port 80 (HTTP):
- Service: Web server (unencrypted)
- Risk: Medium - traffic can be intercepted
- Hardening: Redirect to HTTPS (443), use HSTS headers
- Attacks: MITM, session hijacking, XSS, SQL injection
- Port 443 (HTTPS):
- Service: Encrypted web server
- Risk: Low if using modern TLS
- Hardening: TLS 1.2+, strong cipher suites, HSTS, certificate pinning
- Verify certificate validity and chain
- Port 3306 (MySQL):
- Service: MySQL database
- Risk: High - should NEVER be exposed to internet
- Hardening: Bind to localhost (127.0.0.1), use SSH tunnel or VPN
- Attacks: SQL injection, brute force, credential leaks
- Port 3389 (RDP):
- Service: Windows Remote Desktop
- Risk: High - frequent ransomware attack vector
- Hardening: NLA, strong passwords, MFA, VPN, IP whitelist
- Attacks: BlueKeep (CVE-2019-0708), brute force, ransomware
Port Scanning Techniques:
- TCP SYN Scan (nmap -sS): "Stealth" scan, doesn't complete handshake
- Sends SYN, waits for SYN/ACK (open) or RST (closed)
- Faster than full connect scan
- Requires root/administrator privileges
- TCP Connect Scan (nmap -sT): Completes full 3-way handshake
- Uses OS connect() system call
- Logged by target system (more detectable)
- Works without privileges
- UDP Scan (nmap -sU): Scans UDP ports (DNS, SNMP, DHCP)
- Slower than TCP (no handshake, relies on timeouts)
- ICMP unreachable = closed, no response = open|filtered
- Important for discovering DNS, SNMP vulnerabilities
- Service Version Detection (nmap -sV): Identifies service versions
- Sends probes to open ports
- Matches responses against signature database
- Critical for vulnerability assessment
Risk Levels Explained:
- Critical: Service is inherently insecure (Telnet, FTP, SNMP v1/v2)
- Transmits credentials in cleartext
- No encryption of data
- Action: Disable immediately or replace with secure alternative
- High: Service should not be exposed to internet (databases, RDP, SMB)
- Frequent target of automated attacks
- Known exploits and vulnerabilities
- Action: Restrict to localhost or VPN, firewall by IP
- Medium: Service requires additional hardening (HTTP, SMTP)
- Can be secure with proper configuration
- Consider encryption (TLS/SSL)
- Action: Enable auth, use encryption, monitor access
- Low: Service is reasonably secure (HTTPS, SSH with keys)
- Uses modern encryption
- Follow best practices for configuration
- Action: Keep updated, monitor logs, use strong auth
Security Hardening Best Practices:
- Principle of Least Privilege: Only open ports required for functionality
- Defense in Depth: Multiple layers (firewall, auth, encryption, monitoring)
- Disable Unused Services: Reduce attack surface by stopping unnecessary services
- Use Encryption: TLS/SSL for all internet-facing services
- Strong Authentication: Key-based auth, MFA, strong passwords
- Firewall Rules: Whitelist specific IPs, block by default
- Network Segmentation: Isolate critical services in VLANs or DMZ
- Regular Updates: Patch services for known vulnerabilities (CVEs)
- Monitoring and Logging: Detect intrusion attempts and anomalies
- Fail2ban/IP Blocking: Automatic blocking after failed auth attempts
Common Attack Vectors:
- Brute Force: Automated password guessing (SSH, RDP, FTP)
- Mitigation: Fail2ban, rate limiting, strong passwords, MFA
- Exploiting Known Vulnerabilities: CVEs in outdated software
- Mitigation: Regular patching, vulnerability scanning
- Default Credentials: Services with unchanged default passwords
- Mitigation: Change all defaults immediately after installation
- Service Exploitation: Buffer overflows, RCE vulnerabilities
- Mitigation: Web Application Firewall (WAF), IDS/IPS, sandboxing
Compliance Considerations:
- PCI-DSS: Quarterly vulnerability scans, firewall configuration, disable unnecessary services
- HIPAA: Encryption for ePHI transmission, access controls, audit logging
- SOC 2: Security monitoring, change management, incident response
- CIS Benchmarks: Industry-standard security configurations for services
Tools for Port Scanning:
- nmap: Industry-standard network mapper with extensive features
- masscan: High-speed scanner for large networks
- netcat (nc): Manual port checking and banner grabbing
- Shodan/Censys: Internet-wide port scan databases
- OpenVAS/Nessus: Vulnerability scanners with port scanning capabilities