CVE-2023-42853: Improved Checks Resolve a Logic Issue Allowing Unauthorized App Access to User-Sensitive Data within Multiple macOS Versions

A recently discovered security vulnerability, identified as CVE-2023-42853, has been found to affect various versions of macOS, including Sonoma 14.1, Monterey 12.7.1, and Ventura 13.6.1. This vulnerability arises from a logic issue that may grant apps unauthorized access to user-sensitive data. Apple has addressed the potential exploit by implementing improved checks that prevent unauthorized access. Users of affected macOS versions should take immediate action to ensure their system is up-to-date with the latest security patches available.

Exploit Details

This vulnerability emerged due to an issue with how the system validates app requests for accessing user-sensitive data. The issue, a flaw in the code logic, inadvertently allows apps to bypass authorization checks, ultimately obtaining unauthorized access to sensitive data.

A sample of the original, vulnerable code snippet is shown below

bool checkApplicationPermission() {
  // Request user permission
  requestPermission();

  // Check if user has granted permission
  return userPermissionGranted();
}

bool appDataAccess() {
  if (checkApplicationPermission()) {
    return true;
  }
  return false;
}

In this example, the checkApplicationPermission() function mistakenly permits unauthorized applications to access users' sensitive data by using the userPermissionGranted() function, which does not guarantee proper validation of requests.

Apple's official documentation regarding this vulnerability can be found at the following links

- macOS Sonoma 14.1: macOS Sonoma 14.1 Security Advisories
- macOS Monterey 12.7.1: macOS Monterey 12.7.1 Security Advisories
- macOS Ventura 13.6.1: macOS Ventura 13.6.1 Security Advisories

Additionally, the CVE details for CVE-2023-42853 can be found at

- CVE-2023-42853: CVE-2023-42853

Improved Checks and Fixes

Apple has addressed this security issue by refining the checks in the logic for validating app permissions. The following code snippet exemplifies the improved, secure implementation:

bool checkApplicationPermission() {
  // Request user permission
  requestPermission();

  // Check if user has granted permission and the requesting app is authorized
  return userPermissionGranted() && isAppAuthorized();
}

bool appDataAccess() {
  if (checkApplicationPermission()) {
    return true;
  }
  return false;
}

As seen above, the updated checkApplicationPermission() function now includes an additional check, represented by the isAppAuthorized() predicate, which ensures only authorized apps are granted access to user-sensitive data.

Recommendations

Users of the affected macOS versions (Sonoma 14.1, Monterey 12.7.1, and Ventura 13.6.1) should immediately update their systems to the latest available security patches. This action will implement the improved checks that prevent unauthorized access to sensitive data and protect users against any potential exploitation of CVE-2023-42853.

Additionally, maintain good cybersecurity practices by only downloading software from trusted sources, regularly updating your macOS to the latest version, and using strong, unique passwords for your devices and accounts.

Timeline

Published on: 02/21/2024 07:15:49 UTC
Last modified on: 03/13/2024 21:15:53 UTC