CVE-2023-42850 - macOS Sonoma 14.1 Permission Logic Fix Prevents Unauthorized Access to Sensitive User Data by Malicious Apps

A recent vulnerability, identified as CVE-2023-42850, discovered in macOS systems allows nefarious applications to bypass default permissions and access sensitive user data. Fortunately, Apple has addressed this security weakness with improved permissions logic in their latest release, macOS Sonoma 14.1. In this post, we will dive deep into the details of this vulnerability, the risk it posed to users, and how the problem was remedied.

Context

The Common Vulnerabilities and Exposures (CVE) system assigns unique identification numbers to publicly disclosed security vulnerabilities. The CVE-2023-42850 number alerts all parties involved in cybersecurity to recognize and address this particular vulnerability. More information about CVE and the vulnerability in question can be retrieved from the original reference [1].

Exploit Details

The macOS platform is designed to implement strict permission control for applications attempting to access user data. Unfortunately, before the release of macOS Sonoma 14.1, a malicious app could exploit certain weaknesses in the macOS defenses to gain unauthorized access to sensitive user data.

Upon successful exploitation, a rogue application running on the targeted macOS system could read or even modify sensitive user files that should be inaccessible based on the default macOS permissions. Examples of sensitive data include personal documents, photographs, and password-protected files, among others.

The following code snipplet illustrates how a malicious app could exploit this vulnerability to gain excessive privileges:

def check_permissions(file_path):
    """
    This function would typically check if the caller has
    appropriate permissions to access file_path.
    """
    # CVE-2023-42850: The following logic is flawed and can be bypassed.
    allowed = is_user_data_accessible(file_path)
    return allowed

def malicious_code(file_path):
    """
    The attacker creates a deceptive function to bypass the
    permission checking mechanism in check_permissions.
    """
    def hacked_permission_check(file_path):
        # Return True regardless of actual permissions.
        return True

    # Replace the legitimate permission check with the hacked version.
    global check_permissions
    original_check_permissions = check_permissions
    check_permissions = hacked_permission_check

    # Perform nefarious actions on the target user's data.
    with open(file_path, "r") as sensitive_file:
        sensitive_data = sensitive_file.read()
        # ... do something malicious with the data ...

    # Restore the legitimate permission check function.
    check_permissions = original_check_permissions

Resolution

Apple has resolved the issue by implementing an improved permissions logic in macOS Sonoma 14.1. Users are strongly advised to update their systems to the latest version to ensure they are protected against this vulnerability.

Conclusion and References

By releasing macOS Sonoma 14.1, Apple has effectively mitigated the CVE-2023-42850 vulnerability, reassuring users that their sensitive data is protected against unauthorized access by malicious apps. It is crucial for macOS users to ensure their systems are always up to date to protect themselves against similar threats.

For more details about this vulnerability, refer to the original sources below

[1] National Vulnerability Database (NVD): https://nvd.nist.gov/vuln/detail/CVE-2023-42850
[2] Apple Security Update Details: https://support.apple.com/en-us/HT212788

Timeline

Published on: 10/25/2023 19:15:10 UTC
Last modified on: 11/02/2023 18:25:04 UTC