CVE-2022-1196 - In-depth Analysis of Use-After-Free Vulnerability in Thunderbird and Firefox ESR due to Retained Reference to VR Process

In this post, we will delve into the details of CVE-2022-1196, a critical security vulnerability discovered in Thunderbird < 91.8 and Firefox ESR < 91.8. The vulnerability arises due to the presence of a use-after-free error, which occurs when the unintended reuse of memory occurs after it has been freed. This can lead to unexpected behavior, which, in the worst case, can result in the execution of arbitrary code by attackers.

Vulnerability Description

CVE-2022-1196: A use-after-free vulnerability manifests when a reference to a destroyed VR (Virtual Reality) process is retained and utilized, causing a potentially exploitable crash. This vulnerability affects Thunderbird < 91.8 and Firefox ESR < 91.8.

Let's dive deeper into the details of the vulnerability and understand the exploit.

The vulnerability might arise in the following scenario

class VRProcess {
public:
  void doSomething() {
    // Do something with VR resources
  }
};

VRProcess* vrProcess = new VRProcess();
vrProcess->doSomething();

delete vrProcess;

// The problematic part
vrProcess->doSomething(); // Use after free, the object was already deleted

As seen in the code snippet above, the program creates a new VRProcess object, which is then deleted. However, the program later tries to call the doSomething() method on the deleted object, leading to a use-after-free error.

Mozilla Foundation Security Advisory (MFSA) 2022-12

Mozilla Foundation has officially acknowledged this vulnerability and released security updates to address it. You can find the original advisory here: https://www.mozilla.org/en-US/security/advisories/mfsa2022-12/

CVE-2022-1196 Detail

National Vulnerability Database (NVD) entry for CVE-2022-1196: https://nvd.nist.gov/vuln/detail/CVE-2022-1196

Exploit Details

In order to exploit this vulnerability, an attacker would have to craft a malicious website or content that triggers the use-after-free error in the affected applications, Thunderbird and Firefox ESR. By doing so, the attacker may cause the application to crash or potentially execute arbitrary code, allowing them to compromise the target system.

Here is a high-level overview of the steps an attacker may take to exploit CVE-2022-1196

1. Create a webpage or content that triggers the use-after-free error by retaining a reference to a destroyed VR process and then utilizing it.

2. Entice the victim to visit the malicious webpage or view the content, thus causing the use-after-free error in the affected application.

Mitigation & Recommendations

To protect your system from CVE-2022-1196, it is strongly advised to update Thunderbird and Firefox ESR to their latest versions. Specifically, you should update Thunderbird to version 91.8 or later and Firefox ESR to version 91.8 or later.

Conclusion

CVE-2022-1196 is a critical security vulnerability affecting Thunderbird and Firefox ESR. It can lead to potentially exploitable crashes due to the unintended reuse of memory after it has been freed. To mitigate this vulnerability, users should update their applications to the latest versions and exercise caution when visiting unfamiliar websites or viewing unknown content. Stay secure!

Timeline

Published on: 12/22/2022 20:15:00 UTC
Last modified on: 12/29/2022 20:31:00 UTC