CSP: report-uri

Deprecated
This feature has been removed from the Web standards. Though some browsers may still support it, it is in the process of being dropped. Avoid using it and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.

The deprecated HTTP Content-Security-Policy (CSP) report-uri directive instructs the user agent to report attempts to violate the Content Security Policy. These violation reports consist of JSON documents sent via an HTTP POST request to the specified URI.

Though the report-to directive is intended to replace the deprecated report-uri directive, report-to isn’t supported in most browsers yet. So for compatibility with current browsers while also adding forward compatibility when browsers get report-to support, you can specify both report-uri and report-to:

Content-Security-Policy: ...; report-uri https://endpoint.com; report-to groupname

In browsers that support report-to, the report-uri directive will be ignored.

The directive has no effect in and of itself, but only gains meaning in combination with other directives.

CSP version 1
Directive type Reporting directive
This directive is not supported in the <meta> element.

Syntax

Content-Security-Policy: report-uri <uri>;
<uri>
A URI where to POST the report to.

Examples

See Content-Security-Policy-Report-Only for more information and examples.

Content-Security-Policy: default-src https:; report-uri /csp-violation-report-endpoint/

/csp-violation-report-endpoint/ could for example run a PHP something like the following that logs the JSON detailing the violation and, if the violation is the first one added to the log file, sends an email to an administrator:

<?php

// Start configure
$log_file = dirname(__FILE__) . '/csp-violations.log';
$log_file_size_limit = 1000000; // bytes - once exceeded no further entries are added
$email_address = 'admin@example.com';
$email_subject = 'Content-Security-Policy violation';
// End configuration

$current_domain = preg_replace('/www\./i', '', $_SERVER['SERVER_NAME']);
$email_subject = $email_subject . ' on ' . $current_domain;

http_response_code(204); // HTTP 204 No Content

$json_data = file_get_contents('php://input');

// We pretty print the JSON before adding it to the log file
if ($json_data = json_decode($json_data)) {
  $json_data = json_encode($json_data, JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES);

  if (!file_exists($log_file)) {
    // Send an email
    $message = "The following Content-Security-Policy violation occurred on " .
      $current_domain . ":\n\n" .
      $json_data .
      "\n\nFurther CPS violations will be logged to the following log file, but no further email notifications will be sent until this log file is deleted:\n\n" .
      $log_file;
    mail($email_address, $email_subject, $message,
         'Content-Type: text/plain;charset=utf-8');
  } else if (filesize($log_file) > $log_file_size_limit) {
    exit(0);
  }

  file_put_contents($log_file, $json_data, FILE_APPEND | LOCK_EX);
}

?>

Specifications

Specification Status Comment
Content Security Policy Level 3
The definition of 'report-uri' in that specification.
Editor's Draft No changes.
Content Security Policy Level 2
The definition of 'report-uri' in that specification.
Recommendation Initial definition.

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic Support251423.0No157
FeatureAndroidChrome for AndroidEdge mobileFirefox for AndroidIE mobileOpera AndroidiOS Safari
Basic Support4.4(Yes)?23.0No?7.1

See also

Document Tags and Contributors

 Contributors to this page: sideshowbarker, fscholz, Jonathan_Watt, teoli
 Last updated by: sideshowbarker,