Microsoft ASP.NET Unicode Character Conversion Multiple Cross-Site Scripting Vulnerabilities

Bugtraq ID:	12574
Class:	Input Validation Error
CVE:	CVE-2005-0452
Remote:	Yes
Local:	No
Published:	Feb 16 2005 12:00AM
Updated:	Feb 16 2005 12:00AM
Credit:	Discovery is credited to Andrey Rusyaev.
Vulnerable:	Microsoft ASP.NET 1.1 SP1 Microsoft ASP.NET 1.1 Microsoft ASP.NET 1.0 SP2 Microsoft ASP.NET 1.0 SP1 Microsoft ASP.NET 1.0
Not Vulnerable:

Microsoft ASP.NET Unicode Character Conversion Multiple Cross-Site Scripting Vulnerabilities

It is reported that ASP.NET is prone to various cross-site scripting attacks. These issues when ASP.NET converts Unicode characters ranging from U+ff00-U+ff60 to ASCII.

Apparently, the application fails to properly validate Unicode characters allowing an attacker to craft a malicious link containing arbitrary HTML or script code to be executed in a user's browser.

This can facilitate theft of cookie-based credentials and other attacks.

Microsoft ASP.NET Unicode Character Conversion Multiple Cross-Site Scripting Vulnerabilities

An exploit is not required.

The following proof of concept example is available:
http://www.example.com/attack1.aspx?test=%uff1cscript%uff1ealert('vulnerability')%uff1c/script%uff1e

Microsoft ASP.NET Unicode Character Conversion Multiple Cross-Site Scripting Vulnerabilities

Solution:
Currently we are not aware of any vendor-supplied patches for this issue. If you feel we are in error or are aware of more recent information, please mail us at: [email protected] <mailto:[email protected]>.

Microsoft ASP.NET Unicode Character Conversion Multiple Cross-Site Scripting Vulnerabilities

References:

• Technet Security (Microsoft)
  
• XSS vulnerability in ASP.Net (Andrey Rusyaev)