The security community has recently discovered a new notable vulnerability, CVE-2022-26730, within the macOS Ventura 13. This vulnerability is associated with a memory corruption issue that occurs during the processing of ICC profiles. Attackers can exploit this vulnerability to perform arbitrary code execution, potentially causing severe consequences to affected systems. In this post, we'll dive deep into the details of this issue, discuss example exploitations, and shed light on how system administrators and developers can protect their systems against it.

The Memory Corruption Issue

In essence, the vulnerability results from an inherent weakness within how macOS Ventura 13 handles input validation when processing ICC color profiles. ICC profiles define the color attributes of images, often used by image editing software or graphic applications to ensure color consistency across various devices. The improper validation allows for maliciously crafted images to cause memory corruption, leading to arbitrary code execution.

The original security reference for this vulnerability (CVE-2022-26730) can be found here: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-26730.

Example Exploitation of the Vulnerability

To exploit this vulnerability, an attacker first needs to prepare a malicious image with a manipulated ICC profile. The image must contain data or structures that are invalid or unexpected to the ICC profile processing functionality in macOS Ventura 13. When the user or the system itself tries to process the malicious image, the memory corruption will occur, leading to arbitrary code execution.

To demonstrate the vulnerability, consider the following snippet of code, specifically showing the problematic ICC profile validation:

void process_icc_profile(char *profile_data, uint32_t profile_size) {
    uint32_t signature = *(uint32_t *)(profile_data + 4);
    
    // Lack of proper input validation
    if (signature != EXPECTED_SIGNATURE) {
        printf("Warning: Invalid ICC profile signature.\n");
    }
    
    // Continue processing the ICC profile despite the invalid signature
    ...
}

As shown above, the code does not perform sufficient validation checks on the input profile_data. The system continues processing the ICC profile, even if the signature is invalid, leading to the memory corruption issue.

Protection Against the Vulnerability

Thankfully, the issue has been addressed in the latest version of macOS Ventura 13, via improved input validation. Users and administrators of macOS systems are urged to update to the latest version of the operating system to prevent exploitation of this vulnerability.

To illustrate how to correctly validate the ICC profile data, we provide the following snippet of code demonstrating the proper input validation:

`c
void process_icc_profile(char *profile_data, uint32_t profile_size) {
   uint32_t signature = *(uint32_t *)(profile_data + 4);
   
   // Improved input validation
   if (signature != EXPECTED_SIGNATURE) {
       printf("Error: Invalid ICC profile signature.\n");
       return; // Stop processing the ICC profile
   }
   
   // Continue processing the ICC profile
   ...
}
'''

By applying the proper input validation in the code, it is now ensured that only valid ICC profiles will be processed, preventing memory corruption and ultimately the arbitrariness of code execution.

## Conclusion

CVE-2022-26730 is a critical vulnerability in macOS Ventura 13, which allowed for arbitrary code execution due to memory corruption issues within the processing of ICC profiles. Users should update their macOS systems to the latest version to ensure that proper input validation is implemented, preventing exploitation of this vulnerability. Stay vigilant and always apply security updates as soon as they become available to maintain the security of your systems.

Timeline

Published on: 11/01/2022 20:15:00 UTC
Last modified on: 11/03/2022 13:15:00 UTC