Internet Explorer 5.0 does not properly reset the username/password cache for Web sites that do not use standard cache controls, which could allow users on the same system to access restricted web sites that were visited by other users.
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.
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.