CVE-2023-32419 - iOS and iPadOS Arbitrary Code Execution Vulnerability

In this in-depth write-up, we will discuss a recently-discovered security vulnerability, CVE-2023-32419, affecting Apple's iOS and iPadOS platforms. We will break down the details of the exploit, provide code snippets to help understand it, and link to the original references. Additionally, we will discuss Apple's response and how the issue has been addressed.

Summary

CVE-2023-32419 was identified as a critical security vulnerability that allowed malicious users to remotely execute arbitrary code on devices running iOS or iPadOS. This made it possible for an attacker to gain unauthorized access and control over targeted devices. The issue was present due to inadequate bounds checks within a specific iPhone and iPad software component. Fortunately, Apple resolved this vulnerability in the iOS 16.5 and iPadOS 16.5 updates by implementing improved bounds checks. Users are now safe from this particular exploit, as long as they have updated their devices.

Exploit Details

The CVE-2023-32419 vulnerability was located in a component responsible for processing a specific type of data that an attacker could manipulate. When this specially-crafted malicious data was sent to a vulnerable device, the data would exceed its expected bounds, leading to a buffer overflow. This would allow the attacker to corrupt memory adjacent to the improperly checked buffer. Consequently, control over the device's execution could be hijacked and arbitrary code could be executed remotely.

Let's dive in and see how this might happen in code. Here's an example of a vulnerable function

void process_data(char* input){
    char data_buffer[256];
    int index = ;
    
    while(input[index] != '\'){
        data_buffer[index] = input[index];
        index++;
    }
}

This function copies the contents of the input pointer into a fixed-size data_buffer. However, it doesn't perform any bounds checks to limit the length of the data being processed. This can result in an attempt to write data beyond the allocated buffer, leading to buffer overflow and subsequent memory corruption.

By exploiting this vulnerability, an attacker could force the vulnerable function to write attacker-controlled code into the area beyond the buffer. Once this was done, the attacker could change the program's execution path to the injected code, resulting in arbitrary code execution.

Refer to the following public references that provide further technical details

- MITRE CVE-2023-32419 Details
- Apple Security Updates
- NVD - CVE-2023-32419

Remediation

Apple addressed the CVE-2023-32419 vulnerability through improved bounds checks in its iOS 16.5 and iPadOS 16.5 updates. For instance, the vulnerable function could have been fixed by adding a bounds check:

void process_data_fixed(char* input){
    char data_buffer[256];
    int index = ;
    
    while(input[index] != '\' && index < sizeof(data_buffer) - 1){
        data_buffer[index] = input[index];
        index++;
    }
}

This revised function includes a bounds check, ensuring that the index doesn't exceed the size of data_buffer, preventing buffer overflow and subsequent arbitrary code execution.

To protect devices from this exploit, users should update their iPhone or iPad to iOS 16.5 or iPadOS 16.5 respectively. By doing so, it ensures that devices have the necessary security patches to mitigate the risk posed by CVE-2023-32419.

Conclusion

CVE-2023-32419 was a critical security vulnerability affecting iOS and iPadOS devices that allowed remote attackers to execute arbitrary code, potentially compromising device security and user data. Thanks to Apple's swift response and the release of iOS 16.5 and iPadOS 16.5, the issue has been addressed and no longer poses a threat to devices running updated software.

Stay vigilant and ensure that your devices are updated regularly to maintain the highest level of security and protection against emerging threats like CVE-2023-32419.

Timeline

Published on: 06/23/2023 18:15:00 UTC
Last modified on: 07/27/2023 04:15:00 UTC