If there is a site that should be listed here or if a link goes dead, .

• Alerting services
  • E-Secure-IT Security Alert and Early Warning service
  • iAlert Intelligence Services
  • Secunia Stay Secure : Vulnerability Tracking Service
  • SecurityTracker
  • Sintelli Alert! : security intelligence alert services
  • Symantec DeepSight Alert Services
  • Trace Security : Proactive services
  • TruSecure IntelliShield : security threat/vulnerability alerting service
• @stake
  
• Addressing Common Hacker Exploits
  
• Macromedia Security Zone
  
• AusCERT Advisories and Alerts
  
• CERT/CC Current Activity
  high-impact security incidents and vulnerabilities
  
• Cisco
  
• DOE's CIAC
  
• eEye Digital Security
  
• Exploit news
  
• Exploit World! Microsoft section
  
• Foundstone
  
• ISS
  
• Mandrake
  
• Microsoft Security Bulletin Search
  
• National Infrastructure Protection Center
  
• NTBugtraq: security exploits and security bugs in Windows NT
  Excellent! A must for NT admis, mailing list
  
• NTsecurity
  
• RedHat
  
• SCO
  
• USSR
  
• WEPCrack: cracks 802.11 WEP encryption keys using weakness of RC4 key scheduling.