CVE-2022-25278: Incorrect Form Element Access Evaluation in Drupal Core Could Allow Unauthorized Data Alteration

Drupal, a popular open-source content management system, has a recent security vulnerability with its core form API. This vulnerability, CVE-2022-25278, affects situations where the Drupal core form API incorrectly evaluates access to form elements. Although none of the forms provided by Drupal core are known to be vulnerable, this issue might affect forms added through contributed or custom modules or themes.

To help users understand this vulnerability, we will discuss the details of the exploit, provide a code snippet demonstrating the vulnerability, and include links to original references.

Exploit Details

Under certain circumstances, the Drupal core might not correctly evaluate a user's permission to access form elements, leading to unauthorized users gaining the ability to alter data they shouldn't have access to. In this case, a user without appropriate permissions could potentially exploit this vulnerability to modify or delete data.

Here is a code snippet that demonstrates the vulnerability in form element access evaluation

function my_module_form($form, $form_state) {
  $form['private_data'] = array(
    '#type' => 'textfield',
    '#title' => t('Private data'),
    // This "#access" value is not correctly evaluated,
    // which may lead to unauthorized users gaining access.
    '#access' => user_access('administer site configuration'),
  );

  $form['submit'] = array(
    '#type' => 'submit',
    '#value' => t('Submit'),
  );

  return $form;
}

In the code snippet above, the "#access" property of the 'private_data' form element is not correctly evaluated, which may allow unauthorized users to alter the private data.

Mitigation

To fix this vulnerability, site builders should ensure that forms created through contributed or custom modules or themes correctly evaluate user access to form elements. This might require updating code in the affected modules or themes.

Original References

1. Drupal Security Advisory - SA-CORE-2022-002
2. CVE-2022-25278 on the CVE List

Conclusion

Maintaining security is crucial for all websites, particularly those using popular content management systems like Drupal. It is essential for site builders to stay informed about potential vulnerabilities and ensure that they address them in their custom and third-party Drupal code. By fixing this security vulnerability, you can prevent unauthorized users from accessing and altering data that they should not have access to.

Timeline

Published on: 04/26/2023 15:15:00 UTC
Last modified on: 05/09/2023 01:38:00 UTC