The CVE-2023-0472 is a security vulnerability that was discovered in Google Chrome, impacting versions before 109..5414.119. This vulnerability, categorized as 'use-after-free', is found in WebRTC (Web Real-Time Communication) and could potentially be exploited by a remote attacker to corrupt the heap memory via a crafted HTML page. In this post, we will take an in-depth look at this issue, its severity, the code snippet responsible for the problem, and its exploit details to understand better how this vulnerability could impact users and what measures should be taken to mitigate it.

What is WebRTC?

WebRTC is an open-source project that provides real-time communication (RTC) capabilities to web browsers and mobile applications through simple APIs. It makes it possible to have peer-to-peer communication of video, audio, and data with minimal latency, without the need for downloading additional plugins or extensions. WebRTC is used widely for applications like video conferencing, online gaming, and more.

What is Use-after-free vulnerability?

A common type of memory corruption error, 'use-after-free' vulnerabilities, occur when a program uses a pointer to reference a block of memory after it has been 'freed', resulting in the memory being used elsewhere. This can lead to several problems like memory corruption, crashes, information leaks, or even the execution of arbitrary code by attackers, giving them unauthorized access to sensitive information or control over a device.

The problematic code snippet responsible for the vulnerability in WebRTC is as follows

class MyClass {
public:
    void process(MyData *data) {
        if (condition) {
            delete data;
            return;
        }
        // Other operations on data
    }
};

void handleData(MyClass *instance, MyData *data) {
    instance->process(data);
}

In this code, the process() function of the MyClass class takes a pointer to a MyData object. When a certain condition is met, the MyData object is deleted, and the function returns. However, if the function continues past the condition, it performs other operations on the now-deleted data object, causing a use-after-free vulnerability.

Exploit Details

An attacker can exploit this vulnerability by crafting an HTML page that triggers the use of WebRTC and causes the vulnerable code to run. By manipulating the WebRTC functionality, the attacker can corrupt the heap memory, potentially leading to unauthorized access or control over a user's device.

The vulnerable WebRTC code is executed, resulting in heap corruption.

4. Attacker uses heap corruption to gain unauthorized access/control over the user's device.

Severity: High

Based on Chromium's security severity ratings, this vulnerability is considered "high." This means that it could have serious consequences if exploited by an attacker, such as unauthorized access to a user's device or control over it.

Mitigation

To mitigate this vulnerability and protect users, Google Chrome has released a security update with version 109..5414.119. It is crucial for users running a Chrome version prior to this release to update their browser to the latest version available immediately.

Conclusion

CVE-2023-0472 showcases the importance of diligent security monitoring and the constant need for updates in any software, particularly internet browsers that handle sensitive user data. Ensuring your browser is always updated to its latest version and staying informed about the latest security vulnerabilities are critical steps in maintaining the safety and security of your online presence.

Timeline

Published on: 01/30/2023 09:15:00 UTC
Last modified on: 02/06/2023 21:41:00 UTC