Internet Explorer 4.0 and 5.0 allows a remote attacker to execute security scripts in a different security context using malicious URLs, a variant of the "cross frame" vulnerability.

Internet Explorer 5.0 allows a remote server to read arbitrary files on the client's file system using the Microsoft Scriptlet Component.

Internet Explorer 5.0 allows window spoofing, allowing a remote attacker to spoof a legitimate web site and capture information from the client.

The setup wizard (ie5setup.exe) for Internet Explorer 5.0 disables (1) the screen saver, which could leave the system open to users with physical access if a failure occurs during an unattended installation, and (2) the Task Scheduler Service, which might prevent the scheduled execution of security-critical programs.