Internet Explorer 5.5 and 6.0 does not perform complete security checks on external caching, which allows remote attackers to read arbitrary files.
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2002/ms02-068
http://marc.info/?l=ntbugtraq&m=103909877717345&w=2
http://marc.info/?l=ntbugtraq&m=103824668621672&w=2