Sometimes, an oversight in the implementation of an Operating System (OS) can have critical security implications. This happened with Google Chrome OS in versions before 75..377.80. A remote attacker was able to perform arbitrary read/write operations via a malicious file due to an inappropriate implementation. In this post, we will deep dive into the background, code snippets, links to original references, and exploit details of the vulnerability CVE-2019-13689.

CVE-2019-13689 Overview

The Common Vulnerability and Exposure (CVE) identifier for this issue is CVE-2019-13689. It was first assigned to Chromium, the open-source project that underlies Google Chrome. By classifying this vulnerability's severity as "Critical," the Chromium team acknowledged the potential risk it poses to the security of Chrome OS users.

Vulnerability Background

In versions of Chrome before 75..377.80, Google Chrome OS failed to securely handle files, enabling an attacker to perform arbitrary read and write operations. Through specially crafted files, a remote attacker could exploit this vulnerability to compromise a system, potentially leading to data loss, data theft, or other malicious outcomes.

To understand the root cause of the vulnerability, let's dive into some code snippets.

Code Snippet

Before Chrome OS version 75..377.80, the file handling mechanism did not properly sanitize input when processing files. An attacker could exploit this by creating malicious files that bypass Chrome's security restrictions. While the specific code is omitted for security reasons, an oversimplified example of the vulnerability could look like this:

void process_file(file) {
    read_data_from_file(file);
    // MISSING: Proper Input validation and sanitization
    write_data_to_file(file);
}

In this simplified example, the process_file function failed to properly validate and sanitize the input data from the file. By exploiting this omission, an attacker could accomplish malicious activities such as arbitrary read/write operations.

Official References and Patch

The Chromium security team has documented this vulnerability in detail and has provided a solution. For more information, refer to the official Chromium references:
* Chromium Bug Tracker - CVE-2019-13689
* Chromium Security - Release Update 75..377.80

The Chromium development team patched the vulnerability in version 75..377.80 of Chrome OS. Updating to the latest version of Chrome OS is strongly recommended to mitigate the risk associated with CVE-2019-13689.

Exploit Details

As of now, there are no known public exploits for CVE-2019-13689. The Chromium security team, in collaboration with the Google Chrome OS team, has kept the specifics of the vulnerability under wraps to minimize the risk of exploitation. However, it remains essential to apply the ChromeOS update to protect systems from potential threats.

Conclusion

The inappropriate implementation of OS file handling in Google Chrome on ChromeOS prior to version 75..377.80 exposed users to critical security risks. Given the potential consequences of this vulnerability, it's essential to ensure your ChromeOS devices are updated to at least version 75..377.80. With developers continuously improving the security of software, staying current with updates remains one of the most effective ways to protect your devices and systems from potential threats. Stay safe!

Timeline

Published on: 08/25/2023 19:15:00 UTC
Last modified on: 08/31/2023 14:35:00 UTC