source: https://www.securityfocus.com/bid/14039/info

WhatsUp Professional is prone to an SQL injection vulnerability affecting its Web-based front end. This issue is due to a failure in the application to properly sanitize user-supplied input to the 'login.asp' script before using it in an SQL query.

Successful exploitation could result in a compromise of the application, disclosure or modification of data, or may permit an attacker to exploit vulnerabilities in the underlying database implementation. It should be noted that by supplying a 'or' value through the 'password' parameter, an attacker can gain unauthorized access to an affected site. 

The following proof of concept is available:
Reset the Admin user password with a blank password:
- 'UPDATE WebUser SET sPassword=DEFAULT WHERE sUserName='Admin'--

Elevate Guest user privileges to Admin privileges:
- 'UPDATE WebUser SET nUserRightsMask=-1 WHERE sUserName='guest'--