Core Components
Routers
Function: Route packets between networks, maintain routing tables
- Default credentials
- Outdated firmware
- SNMP misconfigurations
- SNMP enumeration
- Web interface exploitation
- Protocol attacks
Switches
Function: Forward frames within a network segment using MAC addresses
Common Vulnerabilities:
- VLAN hopping
- MAC flooding
- STP attacks
Attack Vectors:
- CAM table overflow
- VLAN tagging manipulation
Firewalls
Function: Filter traffic based on predefined rules
Types:
- Stateless
- Stateful
- Application-layer
- Next-gen (NGFW)
- Rule misconfigurations
- Bypass techniques
- Management interface exposure
IDS/IPS Systems
Function: Monitor and prevent malicious network activity
Types:
- Network-based (NIDS/NIPS): Monitor network traffic
- Host-based (HIDS/HIPS): Monitor individual systems
Evasion Techniques:
- Fragmentation
- Encoding
- Timing attacks
VPN Infrastructure
Function: Secure remote access and site-to-site connections
Types:
- IPSec
- SSL/TLS VPN
- L2TP
- PPTP
- Weak authentication
- Certificate vulnerabilities
- Protocol flaws
Proxy Servers
Function: Intermediate servers for client-server communications
Types:
- Forward proxy: Client-side proxy
- Reverse proxy: Server-side proxy
- Transparent proxy: Invisible to clients
Attack Vectors:
- Proxy chaining
- Authentication bypass
- Cache poisoning
Wireless Access Points (WAPs)
Function: Provide wireless network access
- Weak encryption
- Default credentials
- WPS attacks
Attack Vectors:
- WEP/WPA cracking
- Evil twin attacks
- Deauthentication attacks
Servers & Endpoints
Function: Provide services and host applications
Types:
- Web servers
- Database servers
- File servers
- Domain controllers
Attack Surface:
- Network services
- Applications
- Operating system
Cloud Environments
Function: Virtualized infrastructure and services
Types:
- IaaS: Infrastructure as a Service
- PaaS: Platform as a Service
- SaaS: Software as a Service
- Misconfigurations
- IAM vulnerabilities
- Container escapes
Infrastructure Security Considerations
Defense in Depth
Network infrastructure should implement multiple layers of security controls to protect against various attack vectors. This includes:
- Perimeter Security: Firewalls, IDS/IPS at network boundaries
- Network Segmentation: VLANs, subnets to limit attack propagation
- Access Controls: Authentication and authorization mechanisms
- Monitoring: Continuous surveillance of network traffic
- Incident Response: Procedures for handling security incidents
Common Misconfigurations
Network Architecture Visualization
Understanding network topology is crucial for effective penetration testing. Key elements to identify:
- DMZ (Demilitarized Zone) placement
- Internal network segmentation
- Critical asset locations
- Trust relationships between network segments
- Data flow patterns
Assessment Approach
When conducting infrastructure assessment, follow a systematic approach:
- Network Discovery: Identify live hosts and network ranges
- Service Enumeration: Determine running services and versions
- Vulnerability Assessment: Identify known security issues
- Configuration Review: Analyze security settings
- Documentation: Map network topology and relationships
Key Infrastructure Assessment Tools
Security Monitoring and Logging
Effective infrastructure security requires comprehensive monitoring and logging capabilities:
- Network Flow Analysis: Monitor traffic patterns and anomalies
- Security Event Correlation: Aggregate logs from multiple sources
- Real-time Alerting: Immediate notification of security events
- Forensic Capabilities: Detailed logging for incident investigation
- Regular security assessments and penetration testing
- Keep all systems updated with latest security patches
- Implement strong authentication and access controls
- Monitor and log all network activities
- Maintain accurate network documentation
- Establish incident response procedures