It has been discovered that a use after free vulnerability exists in the App Service within Google Chrome versions prior to 102..5005.61. This vulnerability, assigned as CVE-2022-1870, enables an attacker who successfully persuaded a user to install a malicious extension, to potentially exploit heap corruption via this specially designed Chrome extension.

In this long-read post, we will dive into the technical details of the CVE-2022-1870 vulnerability, the code snippet demonstrating the flaw, and links to the original references. Finally, we'll explore how attackers can exploit this vulnerability and the potential impact of such exploitation.

CVE-2022-1870: The Vulnerability Details

Google Chrome's App Service prior to version 102..5005.61, suffers from a use after free vulnerability. In simple terms, "use after free" refers to a memory corruption flaw that occurs when a program continues to use a pointer after it has been freed from memory. This can result in unexpected behavior, crashes, and potentially allow an attacker to execute arbitrary code.

Exploiting this vulnerability, an attacker who succeeds in convincing a user to install a malicious Chrome extension can potentially exploit heap corruption within the program. Heap corruption, in turn, can lead to a variety of adverse consequences, including information leakage, arbitrary code execution, and application crashes.

Code Snippet Demonstrating the Flaw

To better understand the vulnerability, here is a code snippet that demonstrates the use after free issue, where a certain Chrome Extension API is improperly managed by the App Service:

// Illustrative code snippet highlighting the vulnerable code section
class ExtensionAPI {
public:
  // ... other code ...

  void SomeApiCall() {
    // ... perform some actions ...

    // The following line of code may result in a use after free vulnerability by
    // freeing the memory pointed to by 'pointer_to_ext_api_obj' before it should be
    delete pointer_to_ext_api_obj;

    // The API object is still being used in the below line, even though the memory has been freed
    pointer_to_ext_api_obj->PerformAnotherAction();
  }

private:
  // ... other code and data members ...
};

Please note that this code snippet is for illustrative purposes only and is not an exact reproduction of the vulnerable code within Google Chrome.

Original References

The Chrome Releases Blog provides details on the latest updates and security fixes for Google Chrome, including the updates addressing the CVE-2022-1870 vulnerability. More information about this can be found at the following link:

- Chrome Releases Blog: https://chromereleases.googleblog.com/2023/02/stable-channel-update-for-desktop_15.html

Additionally, further information about the CVE-2022-1870 vulnerability can be found in the National Vulnerability Database (NVD):

- National Vulnerability Database (NVD) - CVE-2022-1870: https://nvd.nist.gov/vuln/detail/CVE-2022-1870

Exploiting the Vulnerability

An attacker looking to exploit the CVE-2022-1870 vulnerability would need to craft a malicious Chrome extension that specifically targets this flaw. Upon successful installation, the attacker could potentially exploit heap corruption to perform a variety of malicious activities, such as gaining unauthorized access to sensitive information, executing arbitrary code, or causing the Chrome browser to crash.

Users can protect themselves against this vulnerability by ensuring they are using an updated version of Google Chrome (102..5005.61 or later). Additionally, it's important for users to be cautious when installing Chrome extensions, particularly from unknown sources, and to maintain a best security practice of regularly updating their software.

Conclusion

The CVE-2022-1870 vulnerability exposes Google Chrome users to potential risks when using older browser versions and installing malicious extensions. It is essential for users to keep their software up to date and exercise caution when downloading and installing extensions. By staying informed about current vulnerabilities and following best security practices, users can minimize the risk of exploitation and maintain a secure browsing experience.

Timeline

Published on: 07/27/2022 22:15:00 UTC
Last modified on: 08/15/2022 11:17:00 UTC