Skip to main content
BuyLog In
General Information
Search in…
Docs > Security Information > Content Security Policy
All docs
V24.1
General Information
Support Services
Installation: Unified Component Installer
Installation: NuGet Packages
Install Updates
Security Information
Security - What You Need to Know
Suppress New Processes Initiated by .NET Controls
Suppress Control Requests to Download Data from External URLs
Safe Deserialization
Content Security Policy
Clipboard Access Policy
Localization
Frequent Support Inquiries
DevExpress EULAs
DevExpress Trademarks
Download CHM

How to Use DevExpress Controls with Content Security Policy (CSP)

  • 4 minutes to read

Content Security Policy (CSP) helps detect and mitigate certain attack vectors, including clickjacking, cross-site scripting (XSS), or other code injection-related attacks.

To enable CSP for DevExpress products, you need to apply platform-specific directives. Specify a Content-Security-Policy header or use the <meta> tag to explicitly define authorized functionality with CSP directives.

ASP.NET Web Forms and Bootstrap

<meta http-equiv="Content-Security-Policy" content="default-src 'self';  
      script-src 'unsafe-inline' 'unsafe-eval' 'self';  
      style-src 'unsafe-inline' 'self';  
      img-src 'self' data:" />

ASP.NET MVC

<meta http-equiv="Content-Security-Policy" content="default-src 'self';  
      script-src 'unsafe-inline' 'unsafe-eval' 'self';  
      style-src 'unsafe-inline' 'self';  
      img-src 'self' data:" />

Blazor

Blazor WebAssembly

<meta http-equiv="Content-Security-Policy"
      content="base-uri 'self';
               default-src 'self';
               img-src data: https:;
               object-src 'none';
               script-src 'self'
                          'sha256-v8v3RKRPmN4odZ1CWM5gw80QKPCCWMcpNeOmimNL2AA='
                          'wasm-unsafe-eval';
               style-src 'self'
                         'unsafe-inline';
               upgrade-insecure-requests;">

Review the following topic for additional information: Content Security Policy for Blazor Apps.

Blazor Server

<meta http-equiv="Content-Security-Policy" 
      content="base-uri 'self';
               default-src 'self';
               img-src data: https:;
               object-src 'none';
               script-src 'self';
               style-src 'self' 
                         'unsafe-inline';
               upgrade-insecure-requests;">

Read the following help topic for additional information: Content Security Policy for Blazor Apps.

BI Dashboard

The following <meta> tag specifies the minimum required directives for the DevExpress Web BI Dashboard:

<head>
<!--...-->
    <meta http-equiv="Content-Security-Policy" content="default-src 'self';
    img-src data: https: http:;
    script-src 'self' 'unsafe-inline';
    style-src 'self' 'unsafe-inline'; "/>
<!--...-->
</head>

Blazor applications require the unsafe-eval rule in the script-src directive. To remove unsafe-eval from the script-src directive, you must remove the Knockout library (loaded by DxDashboard) and reference it globally.

In ASP.NET Core, ASP.NET MVC, ASP Web Forms, and Blazor applications, implement a nonce-based CSP to remove unsafe-inline from script-src and style-src directives.

For more information, review the following platform-specific CSP help topics:

DevExtreme

<meta
    http-equiv="Content-Security-Policy"
    content="default-src 'self'; 
    img-src https://* data:; 
    child-src 'none';" 
/>

Review the following help topic for additional information: Content Security Policy for DevExtreme-powered Applications.

DevExtreme-based ASP.NET Core Controls

Specify the <meta> tag with directives and call the AddCspNonce(String) method:

<meta http-equiv="Content-Security-Policy"
    content="default-src 'self'; img-src https://* data:; child-src 'none';
    script-src 'self' 'nonce-allowed-value';"
/>

@Html.DevExtreme().AddCspNonce("allowed-value")
@(Html.DevExtreme().Button()
    .Text("Submit")
)

Review the following topic for additional information: Content Security Policy for DevExtreme-powered ASP.NET Core Applications.

Reporting

The following <meta> tag specifies the minimum required directives for DevExpress Reports:

<head>
<!--...-->
    <meta http-equiv="Content-Security-Policy" content="default-src 'self';
    img-src data: https: http:;
    script-src 'self' 'unsafe-inline';
    style-src 'self' 'unsafe-inline';
    connect-src 'self';
    worker-src 'self' blob:;
    frame-src 'self' blob:;" />
<!--...-->
</head>

Blazor WebAssembly applications require the unsafe-eval rule in the script-src directive.

In ASP.NET Core, ASP.NET MVC, and ASP.NET Web Forms applications and Blazor applications with JavaScript-based controls, you can remove unsafe-inline from script-src and style-src directives.

For more information, review the following platform-specific CSP help topics:

XAF

XAF Blazor

Apply the following directives in the <head> content of the Pages/_Host.cshtml file:

<head>
    <!--...-->
    <meta http-equiv="Content-Security-Policy"
        content="base-uri 'self';
        block-all-mixed-content;
        default-src 'self';
        img-src data: https:;
        object-src 'none';
        script-src 'self';
        style-src 'self' 'unsafe-inline';
        upgrade-insecure-requests;">
    <!--...-->
</head>

Review the following topic for additional information: Content Security Policy for XAF-powered Blazor Apps.

XAF Web Forms

Apply the following directives in the <head> content of Default.aspx and Login.aspx files:

<head>
    <!--...-->
    <meta http-equiv="Content-Security-Policy" 
          content="default-src 'self';
          script-src 'unsafe-inline' 'unsafe-eval' 'self';
          style-src 'unsafe-inline' 'self';
          img-src 'self' data:" />
    <!--...-->
</head>

Review the following topic for additional information: Content Security Policy for XAF-powered Web Forms Apps.