Stolen credit card numbers, hacked federal computer systems and other high-profile on-line assaults have put many users on their guards and focused the attention of security managers on high-level intrusion-detection systems, chains of firewalls and other high-level defences. But many forget that, no matter how hard they try to secure a site, vulnerabilities built into the fabric of the Internet still leave them at risk – even though measures to shut down the most glaringly common vulnerabilities are easily available.
Simple functions like the ability to request a connection between two machines can create openings that are to blame in about 15 per cent of the attacks that are reported each year, says Fred Baker, chairman of the Internet Engineering Task Force (IETF). That’s because TCP/IP hasn’t changed much since the days of its acceptance as the Arpanet transport protocol.
“[Internet Protocol] was originally written among a cohesive community that had significant internal trust. By default, IP applications assume they should trust people,” Baker says.
Denial-of-service and data hijacking attacks using functions of TCP/IP can be prevented using security functions that can be turned on in most server operating systems, filters built into routers or a new version of IP (Version 6), which is a standard for the public-key infrastructure IPSec protocol.
But those security measures are often ignored.