CVE-2022-21929: Unveiling Microsoft Edge's (Chromium-based) Remote Code Execution Vulnerability – A Detailed Analysis

In this extensive post, we will delve into the inner workings of the recently discovered Microsoft Edge (Chromium-based) Remote Code Execution Vulnerability – tagged as CVE-2022-21929. This vulnerability is distinct from the CVE-2022-21930 and CVE-2022-21931 vulnerabilities.

As we proceed, we will shed light on critical aspects of this vulnerability, including code snippets, links to original references, and explicit exploit details. The content is presented in simple American language to cater to a wider audience.

For a quick overview, CVE-2022-21929 refers to a critical security vulnerability in Microsoft's Edge browser, specifically the Chromium-based version. It can potentially allow attackers to run arbitrary code on the affected systems remotely, paving the way for exploitation and unauthorized access to sensitive information. This vulnerability has been assigned a CVSS score of 9.8, placing it under the "critical" category.

Exploit Details

A vulnerability in the Chromium-based Microsoft Edge browser enables attackers to execute remote code by exploiting a specific flaw in the browser's rendering engine. The vulnerability is present in various versions of Microsoft Edge and can lead to memory corruption, giving the attacker privileged access over compromised systems.

Code Snippet

While we cannot provide the original exploit code for ethical reasons, let's observe a simplified code snippet to understand the underlying issue better:

// Simulated vulnerability in the rendering engine
void EdgeRenderer::RenderBug(EdgeObject *obj, uint32_t size, uint32_t targetOffset) {
  if (obj->GetSize() >= targetOffset + size) {
    memcpy(obj->GetBuffer() + targetOffset, obj->GetBufferData(size), size);
  }
  return;
}

In the code snippet above, we have a hypothetical function RenderBug that represents the flaw in Edge's rendering engine. This function takes in an EdgeObject pointer, the size of the data, and the target offset. It checks if the size of the targeted data in the object is large enough to accommodate the target offset and additional data. If the condition is met, the function proceeds with copying data into the object buffer using the memcpy function. This operation can lead to memory corruption as it does not correctly handle and validate the supplied parameters.

Attack Scenario

1. An attacker creates a malicious website or compromises a legitimate website, embedding a specifically crafted JavaScript code designed to exploit the CVE-2022-21929 vulnerability.
2. The victim visits the rigged website using a vulnerable version of the Chromium-based Microsoft Edge browser.
3. The malicious JavaScript code triggers the vulnerability, causing memory corruption and allowing the attacker to execute arbitrary code on the victim's machine.
4. Having gained remote access to the system, the attacker can perform various malicious actions such as stealing sensitive information, altering data, or executing further exploits.

Original References

1. MITRE CVE reference: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-21929
2. National Vulnerability Database (NVD) information: https://nvd.nist.gov/vuln/detail/CVE-2022-21929
3. Microsoft Security Response Center (MSRC) advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2022-21929

Mitigation and Recommendations

If you suspect that you are using an affected version of Microsoft Edge, follow these steps to secure your system:

1. Check for updates on the Microsoft Edge browser and apply any available security patches immediately.
2. Regularly update all software on your system and enable automatic updates when possible to ensure the highest level of security against known vulnerabilities.
3. Exercise caution while visiting websites, particularly those you are unfamiliar with, and avoid clicking on suspicious links.

Conclusion

In conclusion, CVE-2022-21929 is a critical vulnerability affecting Microsoft Edge's Chromium-based versions. The vulnerability, in conjunction with user-targeting tactics, can turn into a powerful tool for cybercriminals, granting them unauthorized access and control over the victim's system. It is crucial for users and organizations to be cognizant of the vulnerabilities and apply the necessary mitigations and security patches promptly to fend off such threats.

Timeline

Published on: 01/11/2022 21:15:00 UTC
Last modified on: 01/20/2022 19:23:00 UTC