Signature Detail

HTTP: IIS ASP Showcode Disclosure

This signature detects attempts to exploit the Showcode ASP vulnerability in Microsoft IIS. Successful exploitation of this vulnerability can allow an attacker to read arbitrary files on the victim host.

Extended Description

A sample Active Server Page (ASP) script installed by default on Microsoft's Internet Information Server (IIS) 4.0 gives remote users access to view any file on the same volume as the web server that is readable by the web server. IIS 4.0 installs a number of sample ASP scripts including one called "showcode.asp". This script allows clients to view the source of other sample scripts via a browser. The "showcode.asp" script does not perform sufficent checks and allows files outside the sample directory to be requested. In particular, it does not check for ".." in the path of the requested file. The script takes one parameter, "source", which is the file to view. The script's default location URL is: http://www.sitename.com/msadc/Samples/SELECTOR/showcode.asp Similar vulnerabilities have been noted in ViewCode.asp, CodeBrws.asp and Winmsdp.exe.

Affected Products

• Microsoft IIS 4.0
• Microsoft IIS 4.0 Alpha
• Microsoft Site Server 3.0 alpha
• Microsoft Site Server 3.0 i386
• Microsoft Site Server 3.0 SP1 alpha
• Microsoft Site Server 3.0 SP1 i386
• Microsoft Site Server 3.0 SP2 alpha
• Microsoft Site Server 3.0 SP2 i386
• Microsoft Site Server Commerce Edition 3.0 alpha
• Microsoft Site Server Commerce Edition 3.0 i386
• Microsoft Site Server Commerce Edition 3.0 SP1 alpha
• Microsoft Site Server Commerce Edition 3.0 SP1 i386
• Microsoft Site Server Commerce Edition 3.0 SP2 alpha
• Microsoft Site Server Commerce Edition 3.0 SP2 i386

References

• BugTraq: 167
• CVE: CVE-1999-0736
• URL: http://www.securityfocus.com/infocus/1317
• URL: http://www.microsoft.com/technet/security/bulletin/ms99-013.asp