CRITICAL
Rule Definition
XSS is the second most prevalent issue in the OWASP Top 10, and is found in around two thirds of all applications.
Automated tools can find some XSS problems automatically, particularly in mature technologies such as PHP, J2EE / JSP, and ASP.NET.
Remediation
Review the source code and have the value of the property EnableViewStateMacse to false.
Violation Code Sample
<system.web>
<pages EnableViewStateMac ="false" />
</system.web>
Fixed Code Sample
<system.web>
<pages EnableViewStateMac ="true" />
</system.web>
//or
Default value is set for true...
So no tag found in the file is True.
<system.web>
<!--<pages EnableViewStateMac ="false" />-->
</system.web>
Reference
https://docs.microsoft.com/fr-fr/dotnet/api/system.web.ui.page.enableviewstatemac?view=netframework-4.7.2
Related Technologies
Technical Criterion
CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
About CAST Appmarq
CAST Appmarq is by far the biggest repository of data about real IT systems. It's built on thousands of analyzed applications, made of 35 different technologies, by over 300 business organizations across major verticals. It provides IT Leaders with factual key analytics to let them know if their applications are on track.