Description

IISv5 has a "Hit-highlighting" functionality that opens some site object and highlights some part of it, that has had a transversal vulnerability in the past. Now it can be used to bypass the IIS authentication.

Remediation

Protect the files from the NTFS filesystem instead of relying on the IIS protection.
Microsoft recommends not to use IISv5 and update to IISv6.

References

Related Vulnerabilities