NETWORK SECURITY HACKS *

Transcription

1 NETWORK SECURITY HACKS * Andrew %pckhart Ji O'REILLY* Beijing Cambridge Farnham Koln Paris Sebastopol Taipei Tokyo

2 Contents Credits Preface ix xi Chapter 1. Unix Host Security 1 1. Secure Mount Points 2 2. Scan for SUID and SGID Programs 3 3. Scan For World- and Group-Writable Directories 5 4. Create Flexible Permissions Hierarchies with POSIX ACLs 5 5. Protect Your Logs from Tampering 8 6. Delegate Administrative Roles Automate Cryptographic Signature Verification Check for Listening Services Prevent Services from Binding to an Interface Restrict Services with Sandboxed Environments Use proftp with a MySQL Authentication Source Prevent Stack-Smashing Attacks Lock Down Your Kernel with grsecurity Restrict Applications with grsecurity Restrict System Calls with Systrace Automated Systrace Policy Creation Control Login Access with PAM Restricted Shell Environments Enforce User and Group Resource Limits Automate System Updates 45

3 Chapter 2. Windows Host Security Check Servers for Applied Patches Get a List of Open Files and Their Owning Processes List Running Services and Open Ports Enable Auditing Secure Your Event Logs Change Your Maximum Log File Sizes Disable Default Shares Encrypt Your Temp Folder Clear the Paging File at Shutdown Restrict Applications Available to Users 63 Chapter 3. Network Security Detect ARP Spoofing Create a Static ARP Table Firewall with Netfilter Firewall with OpenBSD's PacketFilter Create an Authenticated Gateway Firewall with Windows Keep Your Network Self-Contained Test Your Firewall MAC Filtering with Netfilter Block OS Fingerprinting Fool Remote Operating System Detection Software Keep an Inventory of Your Network Scan Your Network for Vulnerabilities Keep Server Clocks Synchronized Create Your Own Certificate Authority Distribute Your CA to Clients Encrypt IMAP and POP with SSL Set Up TLS-Enabled SMTP Detect Ethernet Sniffers Remotely Install Apache with SSL and suexec Secure BIND Secure MySQL Share Files Securely in Unix 130 vi I Contents

4 Chapter 4. Logging Run a Central Syslog Server Steer Syslog Integrate Windows into Your Syslog Infrastructure Automatically Summarize Your Logs Monitor Your Logs Automatically Aggregate Logs from Remote Sites Log User Activity with Process Accounting 154 Chapter 5. Monitoring and Trending Monitor Availability Graph Trends Run ntop for Real-Time Network Stats Audit Network Traffic Collect Statistics with Firewall Rules Sniff the Ether Remotely 172 Chapter 6. Secure Tunnels Set Up IPsec Under Linux Set Up IPsec Under FreeBSD Set Up IPsec in OpenBSD PPTP Tunneling Opportunistic Encryption with FreeS/WAN Forward and Encrypt Traffic with SSH Quick Logins with SSH Client Keys Squid Proxy over SSH Use SSH as a SOCKS Proxy Encrypt and Tunnel Traffic with SSL Tunnel Connections Inside HTTP Tunnel with VTun and SSH Automatic vtund.conf Generator Create a Cross-Platform VPN Tunnel PPP 216 Chapter 7. Network Intrusion Detection Detect Intrusions with Snort Keep Track of Alerts 224 Contents I vii

5 84. Real-Time Monitoring Manage a Sensor Network Write Your Own Snort Rules Prevent and Contain Intrusions with Snort_inline Automated Dynamic Firewalling with SnortSam Detect Anomalous Behavior Automatically Update Snort's Rules Create a Distributed Stealth Sensor Network Use Snort in High-Performance Environments with Barnyard Detect and Prevent Web Application Intrusions Simulate a Network of Vulnerable Hosts Record Honeypot Activity 265 Chapter 8. Recovery and Response Image Mounted Filesystems Verify File Integrity and Find Compromised Files Find Compromised Packages with RPM Scan for Root Kits Find the Owner of a Network 278 Index 281 viii I Contents