CVE-2023-27935 - macOS Vulnerability Fixed with Improved Bounds Checks: What You Need to Know

CVE-2023-27935 is a major security vulnerability that was recently discovered in macOS systems. The issue allowed remote users to potentially cause unexpected app termination or even execute arbitrary code on the targeted system. Fortunately, the vulnerability was addressed by Apple in the form of improved bounds checks. This fix was released as a part of macOS Ventura 13.3, macOS Monterey 12.6.4, and macOS Big Sur 11.7.5 updates. In this post, we will delve into the details of this vulnerability, discuss the associated code snippets, provide links to original references, and explore the exploits identified.

Vulnerability Details

The vulnerability can be traced back to an issue with the bounds checks in a specific section of the macOS systems. Poorly implemented bounds checks could allow remote attackers to manipulate the system, potentially leading to app crashes or arbitrary code execution. It is important to note that this vulnerability has a CVE identifier, which is assigned by the Common Vulnerabilities and Exposures (CVE) online database in order to track security issues.

Code Snippet

To understand the vulnerability, let's take a look at the code snippet below, which demonstrates an example where the bounds checks were not properly implemented:

int vulnerable_function(char *input) {
    char buffer[1024];

    strcpy(buffer, input);

    return ;
}

In the code snippet above, the strcpy function is used to copy the input string into a fixed-size buffer. However, there is no check to ensure that the length of the input string is less than the size of the buffer. This could potentially lead to a buffer overflow, which in turn, could be exploited by attackers.

Exploit Details

While there have been no confirmed reports of this vulnerability being exploited in the wild, it is still important to remain vigilant and understand how the exploit might have been carried out. A knowledgeable attacker could potentially send a crafted input to the vulnerable function in order to cause a buffer overflow.

Upon successful exploitation, the attacker would then have the ability to crash the application or execute arbitrary code, depending on the specific circumstances of the vulnerable system. For instance, the attacker might have been able to leverage this ability to compromise sensitive user data or even perform a variety of malicious tasks remotely.

Original References

To learn more about the CVE-2023-27935 vulnerability and the fixes implemented by Apple, you can refer to the following original sources:

1. Apple's Official Security Advisory
2. CVE-2023-27935 Entry in the CVE Database
3. NIST's National Vulnerability Database Entry for CVE-2023-27935

Conclusion

Security vulnerabilities such as CVE-2023-27935 are a critical issue that must be addressed promptly in order to protect the safety of the affected systems and users. Thankfully, Apple has implemented improved bounds checks as a part of the macOS Ventura 13.3, macOS Monterey 12.6.4, and macOS Big Sur 11.7.5 updates. As a result, the possibility of exploitation in the wild has been significantly reduced.

We strongly recommend that users promptly update their macOS systems to the latest versions to ensure the highest level of security. Additionally, it is crucial to stay informed about ongoing security developments and always prioritize the implementation of security patches to protect against vulnerabilities.

Timeline

Published on: 05/08/2023 20:15:00 UTC
Last modified on: 05/11/2023 20:35:00 UTC