Exposing this specific version can lead an attacker to test for the following critical flaws:
XSS vulnerabilities can occur in web applications built on top of ASP.NET, allowing attackers to inject malicious scripts into content from otherwise trusted websites. x-aspnet-version 4.0.3 vulnerabilities
curl -s -D - https://yourdomain.com/ -o /dev/null | grep -i X-AspNet-Version Exposing this specific version can lead an attacker
Removing X-AspNet-Version is for .NET 4.0.3. Because the framework itself is unsupported, you must: x-aspnet-version 4.0.3 vulnerabilities
When an attacker sees this header, they know the server is running a version of .NET Framework 4.x. If the server is not regularly patched via Windows Update , it may be susceptible to legacy vulnerabilities tied to the 4.0 runtime. 2. Major Known Vulnerabilities