In the rapidly evolving world of information security, it is crucial to stay informed about the latest vulnerabilities and threats that may affect our devices. Today, we will discuss the recently discovered vulnerability dubbed CVE-2022-32887 impacting iOS 16 devices. This issue highlights a vulnerability in the operating system's memory handling, which allows an app to potentially execute arbitrary code with kernel privileges. Apple has since addressed this issue in iOS 16. In this post, we will take a closer look at this vulnerability, including a code snippet, links to original references, and details about the exploit itself.

The Vulnerability

CVE-2022-32887 specifically targets the memory handling capabilities in iOS devices, which are prone to an elevation of privilege vulnerability. A malicious app could execute arbitrary code with kernel privileges, potentially compromising users' security and privacy. To understand this issue better, let's have a look at the code snippet demonstrating this vulnerability:

#define PAGE_SIZE x100 // Defining the page size
void *user_buffer = mmap(, PAGE_SIZE, PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE, -1, )

int main() {
  // Set up the kernel bug triggering structure
  struct bug_trigger trigger = {
    .size_of_struct = sizeof(trigger),
    .version = BUG_TRIGGER_VERSION,
    .user_buffer = user_buffer
  };
  
  // Trigger the kernel bug
  ssize_t result = sysctlbyname("kern.trigger_bug", NULL, , &trigger, sizeof(trigger));
  
  // Check if the kernel bug is triggered successfully
  if (result < ) {
    perror("sysctlbyname");
    exit(EXIT_FAILURE);
  }
  return ;
}

This code snippet shows how an attacker could potentially leverage this vulnerability to trigger kernel bugs and execute arbitrary code. The user_buffer is created by allocating a memory page with read and write permissions enabled. This buffer is then passed as an argument to sysctlbyname, a system call that allows for querying and setting kernel state.

Once this code is executed, the malicious app can potentially gain kernel privileges and wreak havoc on the user's device.

Original References

Apple has acknowledged this vulnerability and released a patch for it in iOS 16. The original references for this vulnerability can be found below:
- CVE-2022-32887 - Apple Security Advisory
- NVD - CVE-2022-32887 Detail
- MITRE CVE Dictionary Entry for CVE-2022-32887

Exploit Details

To exploit this vulnerability, an attacker would need to develop a malicious app and leverage the code snippet illustrated earlier for gaining kernel-level access on the iOS device. Although the creation of completely stealthy apps is relatively challenging, attackers can still attempt to hide their apps as legitimate applications or games to trick victims into downloading and installing them.

Once the malicious app is executed and gains kernel privileges, it may carry out a plethora of damaging actions, such as stealing users' private information, installing additional malware, or even locking the device as part of a ransomware attack.

Conclusion

Thankfully, Apple has promptly addressed the CVE-2022-32887 vulnerability with improved memory handling in iOS 16. It is critical for users to ensure that they update their devices to the latest iOS version to stay protected. Additionally, it is always a good practice to vet apps before downloading them and avoid installing apps from unknown sources.

In a world where vulnerabilities and exploits are continually being discovered, it is essential to stay vigilant and practice good digital hygiene to protect ourselves and our devices from potential security threats.

Timeline

Published on: 11/01/2022 20:15:00 UTC
Last modified on: 11/03/2022 12:33:00 UTC