Apple's macOS, like any other operating system, needs to be secured against potential threats and vulnerabilities. In this particular case, a use-after-free vulnerability (CVE-2023-40404) was discovered in macOS Sonoma 14.1, and has since been fixed. This post aims to provide an in-depth analysis of the vulnerability, its potential impact, and offers insights on code snippets related to the flaw. We will also explore references to the original security advisories in an attempt to understand the gravity of the vulnerability.

Vulnerability Details

CVE-2023-40404 addresses a use-after-free issue in macOS Sonoma 14.1. This vulnerability can allow an attacker to execute arbitrary code with kernel privileges, leading to a significant compromise in system security.

A use-after-free vulnerability occurs when an application continues to use a pointer after it has been freed, creating a potential opportunity for arbitrary code execution. The macOS kernel is responsible for controlling access to system resources, and a vulnerability enabling execution of arbitrary code with kernel privileges could allow an attacker to take full control of the affected system.

The following code snippet illustrates a simple example of a use-after-free vulnerability

#include <stdlib.h>
#include <string.h>

int main() {
    char *ptr = (char*) malloc(10);
    strcpy(ptr, "Hello");

    free(ptr); // ptr is now a dangling pointer

    strcpy(ptr, "World"); // use-after-free vulnerability
    return ;

In this example, the ptr variable is first allocated memory using malloc and assigned the value "Hello". After that, the memory is freed with free(ptr), but ptr is not set to NULL. Consequently, ptr still points to a memory location that has been freed, and strcpy() operation introduces the use-after-free vulnerability.

While the example above is basic and straightforward, the actual context of the vulnerability in macOS Sonoma 14.1 is far more complex.

Original References & Security Advisories

Apple has issued a security advisory for macOS Sonoma in their security updates page. You can access the detailed release notes here. CVE-2023-40404 is among the vulnerabilities mentioned in the notes.

Additionally, you can find more details on the CVE-2023-40404 vulnerability itself on the MITRE CVE page and on the NIST National Vulnerability Database (NVD) page.

Exploit Details

To exploit the use-after-free vulnerability detailed above, an attacker would first need to trigger a specific condition in an app to cause the dangling pointer. Then, they must reuse the freed memory for their own malicious purposes. Although this is a relatively challenging exploitation process, a successful attack could allow execution of arbitrary code with kernel privileges, effectively giving the attacker complete control over the affected system.

For macOS users, it is crucial to update to the latest macOS version, macOS Sonoma 14.1, to ensure that their systems are protected from this vulnerability.


In this post, we delved into the CVE-2023-40404 use-after-free vulnerability discovered in Apple's macOS Sonoma 14.1. This issue has now been addressed, and it is imperative for users to update their systems to ensure the security of their devices. We also discussed the exploit details and examined code snippets to offer insights on how the vulnerability works. Stay updated with the latest security patches and ensure the safety of your macOS device.


Published on: 10/25/2023 19:15:09 UTC
Last modified on: 11/02/2023 17:53:55 UTC