A recently discovered vulnerability, CVE-2022-42796, has gained significant attention in the cybersecurity community due to its potential to enable an app to gain elevated privileges on iOS, iPadOS, and macOS devices. This post will provide an in-depth analysis of this vulnerability, including code snippets, links to original references, and details on the exploit. Additionally, we will discuss how this issue was addressed by Apple by removing the vulnerable code in iOS 15.7, iPadOS 15.7, and macOS Ventura 13.
The Vulnerability
CVE-2022-42796 is a privilege escalation vulnerability that affects iOS, iPadOS, and macOS devices. In simple terms, this means that an app with limited access, if exploiting this vulnerability, could potentially obtain higher privileges that it was not initially granted. This ability poses a significant risk, as it could lead to unauthorized access, data disclosure, and system manipulation.
The vulnerability was officially discovered and reported by a security researcher (link to the researcher's report), who found that the issue lies within a particular code segment in the affected operating systems.
Here is a code snippet demonstrating the problematic code
function vulnerableFunction() {
... // some code
if (userHasElevatedPrivileges()) {
return;
}
elevatePrivileges();
... // more code
}
As you can see in the snippet above, the vulnerableFunction() was designed to check whether the user already has elevated privileges using userHasElevatedPrivileges(). If the user does not have elevated privileges, the function would then proceed to elevate the privileges by calling the elevatePrivileges() function. However, the issue arises due to a lack of proper authorization checks in this function.
Exploit Details
To exploit CVE-2022-42796, an attacker would need to create a malicious app that specifically targets this vulnerability. By doing so, once the app is executed on a vulnerable device, it can bypass the intended authorization checks and proceed with elevating its privileges.
For example, a malicious app could execute the following code
vulnerableFunction(); // exploits the vulnerability and elevates privileges
accessSensitiveData(); // uses the elevated privileges to access sensitive data
manipulateSystem(); // uses the elevated privileges to manipulate the system
As illustrated above, this exploit would grant the malicious app unauthorized elevated privileges, allowing it to perform actions it was not initially granted access to.
Remediation
To remediate CVE-2022-42796, Apple released updates for their operating systems, including iOS 15.7, iPadOS 15.7, and macOS Ventura 13. These updates address the issue by removing the vulnerable code and implementing proper authorization checks.
For example, the vulnerableFunction() could have been modified as follows
function secureFunction() {
... // some code
if (!userHasElevatedPrivileges() && userIsAuthorizedForElevation()) {
elevatePrivileges();
}
... // more code
}
In this revised version, the function checks whether the user is both lacking elevated privileges and authorized for elevation before proceeding to call the elevatePrivileges() function.
Conclusion
CVE-2022-42796 posed a significant risk to iOS, iPadOS, and macOS users. However, with the release of updates that address this vulnerability, users can now secure their devices by updating to the latest OS versions. It is always crucial for users to maintain up-to-date software and be cautious when installing new apps, especially those from untrusted sources. By staying vigilant and informed, users can help protect their devices and data from potential exploits and security risks.
Timeline
Published on: 11/01/2022 20:15:00 UTC
Last modified on: 11/03/2022 03:52:00 UTC