"CVE-2023-5855: Use After Free Vulnerability in Google Chrome Reading Mode and its Exploitation"

In the ever-evolving world of cybersecurity, it is critical to stay informed about the latest vulnerabilities and exploits that could affect the technologies we use every day. One such vulnerability was discovered in Google Chrome's Reading Mode, which is widely used by millions of users rely on to enjoy a clutter-free reading experience.

This blog post will provide an in-depth analysis of CVE-2023-5855, a use-after-free vulnerability in Google Chrome's Reading Mode, which affects versions prior to 119..6045.105. We will discuss the technical details of this vulnerability, how it can be exploited, and the necessary steps to mitigate its risk. So, let's dive into the details.

CVE-2023-5855 Overview

CVE-2023-5855 is a use-after-free vulnerability in Google Chrome's Reading Mode, which affects versions prior to 119..6045.105. This vulnerability has a Chromium security severity rating of "Medium". A remote attacker who can successfully exploit this vulnerability could potentially cause heap corruption by convincing a user to engage in specific user interface (UI) gestures.

Original references

According to the official Chromium security issues list, this vulnerability was initially reported here:

- Chromium Security Issues List

The vulnerability was assigned the CVE identifier "CVE-2023-5855"

- CVE-2023-5855

The following code snippet highlights the problematic area in the Reading Mode implementation

void ReadingMode::onTriggerEvent(Event* event) {
  if (event->type() == EventType::UserGesture) {
    onGestureEvent(static_cast<UserGestureEvent*>(event));
  } else {
    // ...
  }
}

In the code above, the 'onTriggerEvent()' function receives an 'Event*' pointer, which is subsequently cast to a 'UserGestureEvent*' type within the 'onGestureEvent()' function. However, it fails to properly verify the type of event before making this cast, leading to the use-after-free vulnerability.

Exploit Details

To exploit this vulnerability, an attacker must first convince a user to visit a malicious website or open a specifically crafted URL. The attacker's aim is to trigger specific UI gestures (such as swipes, taps, or clicks) that could cause the vulnerable 'onTriggerEvent()' function to be executed.

Upon successful execution of the crafted UI gestures, the heap corruption occurs, leading to possible execution of arbitrary code or browser crashes. In the worst-case scenario, using this vulnerability as a starting point, the attacker could execute code with the same privileges as the user running Chrome, potentially causing further damage.

Mitigation Steps

To mitigate the risks associated with this vulnerability, users should update their Google Chrome browser to version 119..6045.105 or later. Here's how to check and update your Chrome browser:

Click "Help" > "About Google Chrome".

4. This will open a new page, where the browser checks for updates and applies them automatically if available.

Conclusion

Understanding and addressing vulnerabilities like CVE-2023-5855 demonstrates the importance of staying up-to-date when it comes to software versions and security advisories. By doing so, users can protect themselves from potential threats and maintain a safer online presence.

As always, it's essential to keep your software current and follow security best practices to minimize the risks associated with cybersecurity threats. Now that you're aware of the CVE-2023-5855 vulnerability, make sure to update your Google Chrome browser to the latest version as soon as possible. Stay safe!

Timeline

Published on: 11/01/2023 18:15:10 UTC
Last modified on: 11/14/2023 03:15:11 UTC