CVE-2023-32378: Use-After-Free Vulnerability in macOS Systems Allowing Kernel Privilege Escalation

Overview

The vulnerability identified as CVE-2023-32378 is a significant security flaw that affects various versions of macOS. The issue primarily concerns a use-after-free problem that was addressed with improved memory management. If exploited successfully, this vulnerability could permit malicious applications to execute arbitrary code with kernel privileges, thus leading to potential system compromise or data leakage. Due to the severity and potential impact of this vulnerability, it is crucial for system administrators, security professionals, and macOS users to understand its nature and implement appropriate mitigation strategies.

Vulnerability Summary

CVE ID: CVE-2023-32378
Severity: High (CVSS 7.8)
Attack Vector: Local
Privileges Required: Low
User Interaction: Required
Impact: A successful exploit of this vulnerability could result in arbitrary code execution with kernel privileges, potentially leading to system compromise and data leakage.

Affected Products

Product | Affected Versions

macOS Ventura | 13.3
macOS Big Sur | 11.7.5
macOS Monterey | 12.6.4

How the Exploit Works

At its core, the CVE-2023-32378 vulnerability is a use-after-free issue. This type of vulnerability occurs when a chunk of memory is freed (or deleted) while references to that memory space still exist. In the case of CVE-2023-32378, a malicious application can exploit this issue by manipulating these references to execute arbitrary code with kernel privileges.
In a typical scenario, an attacker would need to trick a user into running a malicious application on their system. Once the application is running, it can exploit the use-after-free vulnerability to execute arbitrary code with elevated privileges, potentially taking complete control over the affected system.

Conceptual Example Code

While the specifics of the exploit code would depend on numerous factors, the conceptual example below illustrates how an attacker might attempt to exploit the use-after-free vulnerability:

#include <stdio.h>
#include <stdlib.h>
int main() {
// Allocate memory for data
int *data = malloc(10 * sizeof(int));
if (data == NULL) {
printf("Memory not allocated.\n");
exit(0);
}
// Use the allocated memory
for (int i=0; i<10; i++) {
data[i] = i+1;
}
// Free the allocated memory
free(data);
// Use-after-free vulnerability exploit
// The data pointer is still accessible here even after freeing memory
for (int i=0; i<10; i++) {
printf("%d\n", *(data+i));
}
return 0;
}

This code is a simplified example and doesn’t include the specificities of an actual exploit. However, it demonstrates the core concept of the use-after-free vulnerability: accessing memory after it has been freed, which could lead to unexpected behavior or system compromise.