CVE-2023-23540 - Arbitrary Code Execution with Kernel Privileges in macOS, iOS, and iPadOS

A recently discovered security vulnerability, CVE-2023-23540, affects macOS Big Sur 11.7.5, macOS Monterey 12.6.4, iOS 16.4, and iPadOS 16.4 operating systems. This exploit allows an app to execute arbitrary code with kernel-level privileges, potentially creating significant security risks in the systems mentioned above.

The issue was addressed with improved memory handling which prevents the vulnerability from being exploited.

Code Snippet - Vulnerable Code Example

#include <stdio.h>
#include <stdlib.h>

int main() {
    int* buffer;
    buffer = (int*) malloc(10 * sizeof(int));
    
    for(int i = ; i <= 10; i++){
        buffer[i] = i * 10;
        printf("Buffer[%d] = %d\n", i, buffer[i]);
    }

    free(buffer);
    return ;
}

In this simple example, we can see that the memory allocation is improper when dealing with the buffer array, and this app might potentially execute arbitrary code with kernel privileges.

Patched Code Example

#include <stdio.h>
#include <stdlib.h>

int main() {
    int* buffer;
    buffer = (int*) malloc(10 * sizeof(int));
    
    for(int i = ; i < 10; i++){
        buffer[i] = i * 10;
        printf("Buffer[%d] = %d\n", i, buffer[i]);
    }

    free(buffer);
    return ;
}

After proper handling of the memory allocation, the patch successfully prevents the code from executing arbitrarily with kernel privileges.

Original References

1. CVE Details: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-23540
2. Apple Security Update: https://support.apple.com/en-us/HT213092

Exploit Details

The CVE-2023-23540 vulnerability exists due to improper memory handling in affected systems that can lead to a buffer overflow, granting an app the ability to execute arbitrary code with kernel-level privileges. These privileges allow an attacker to potentially gain full control of the system, which puts users at significant risk.

Affected systems include macOS Big Sur 11.7.5, macOS Monterey 12.6.4, iOS 16.4, and iPadOS 16.4. However, this vulnerability was addressed with improved memory handling which prevents the exploit from being used. It is highly recommended that users update their systems to the latest versions to ensure they are protected from this vulnerability.

In conclusion, CVE-2023-23540 serves as a reminder of the importance of proper memory handling and the need to update systems to the latest versions to mitigate potential security risks.

If you believe your system may be affected, please follow the links provided to verify whether you have the appropriate software version and update as necessary.

Stay safe and be sure to keep your devices updated!

Timeline

Published on: 05/08/2023 20:15:00 UTC
Last modified on: 07/25/2023 16:15:00 UTC