Security researchers have discovered a critical vulnerability, identified as CVE-2022-2743, in Google Chrome on Chrome OS and Lacros. The issue is related to an integer overflow in the Window Manager component, which may lead to an out of bounds memory write if users engage in specific UI interactions. Google has since acknowledged the vulnerability and rated its severity as 'High.'

In this post, we will dive deep into the CVE-2022-2743 vulnerability, provide code snippets, and discuss the exploit details. We will also provide links to original references and outline the necessary steps to stay protected.

Description of the Vulnerability

CVE-2022-2743 is an integer overflow vulnerability in the Window Manager in Google Chrome on Chrome OS and Lacros, prior to version 104..5112.79. A remote attacker could exploit this vulnerability by convincing a user to engage in specific UI interactions, which would then result in an out of bounds memory write. It is a dangerous vulnerability as it may lead to memory corruption and has the potential to allow arbitrary code execution within the context of the vulnerable application.

Exploit Details

The integer overflow vulnerability originates from the Window Manager's handling of certain UI interactions. When Chrome receives a malicious request, it results in an integer overflow condition that could cause memory corruption.

Consider the following code snippet, which illustrates the vulnerable UI interaction

void WindowManager::UpdateWindowSize(int width, int height) {
  uint32_t new_width = static_cast<uint32_t>(width);
  uint32_t new_height = static_cast<uint32_t>(height);

  uint64_t size = new_width * new_height;

  if (size > kMaxMemorySize) {
    // Handle memory overflow
    return;
  }

  // Perform memory allocation and update
  Window* window = CreateNewWindow(new_width, new_height);
}

In the example above, the new_width and new_height variables are used to calculate the window's size. If the product of the width and height is greater than the allowed maximum memory size (kMaxMemorySize), the UpdateWindowSize() function should handle the overflow gracefully. However, due to the integer overflow, the size calculation fails, and the check does not prevent the vulnerability.

To exploit this vulnerability, an attacker would need to craft specific UI interactions to trigger the integer overflow. The attacker could then potentially gain control of the compromised system by leveraging the out-of-bounds memory write issue.

1. Google Chrome Security Update
2. CVE-2022-2743 - NIST National Vulnerability Database

Mitigation

Users should update their Google Chrome browser on Chrome OS and Lacros to the latest version (104..5112.79 or later) immediately to prevent exploitation of this vulnerability. To update your browser, follow the steps below:

Conclusion

CVE-2022-2743 is a high-severity vulnerability that could wreak havoc on affected systems. Prompt updating of Google Chrome on Chrome OS and Lacros to the latest version is necessary to avoid possible exploits. Staying vigilant about potential security issues and keeping software up-to-date are crucial aspects of personal and professional cybersecurity practices.

Timeline

Published on: 01/02/2023 23:15:00 UTC
Last modified on: 01/09/2023 19:15:00 UTC