CVE-2023-5849: Integer Overflow in USB Handling Puts Google Chrome Users at Risk of Heap Corruption Exploitation

A recently identified exploit, CVE-2023-5849, highlights a critical vulnerability within Google Chrome versions earlier than 119..6045.105. This vulnerability is caused by an integer overflow in the handling of Universal Serial Bus (USB) connections, presenting a risk that could allow remote attackers to potentially manipulate heap corruption—all by using a maliciously crafted HTML page. Given the severity of this security concern, understanding the details around this exploit is paramount for both developers and users.

Technical Details

The CVE-2023-5849 exploit arises from a frequently-occurring programming error—integer overflow. As a result of this, the handling of USB connections is negatively impacted. Researchers have attributed this vulnerability to the Chromium project, the foundation for Google Chrome. Specifically, this vulnerability affects the WebUSB API, which provides direct access to USB devices from web pages.

To further explain, here is a simplified code snippet that demonstrates the integer overflow

size_t bufferSize = numOfElements * sizeOfElement;
...
void* buffer = malloc(bufferSize);
if (!buffer) {
    // Handle memory allocation error
    return;
}

During the multiplication of numOfElements and sizeOfElement, if the resultant value is large enough, wrapping may occur, ultimately leading to an improperly sized buffer. Consequently, this too-small buffer can be manipulated by an attacker to exploit heap corruption, which may lead to unauthorized code execution or information disclosure.

Fortunately, the resolution of this vulnerability stems from incorporating proper checks for integer overflow:

if (__builtin_umul_overflow(numOfElements, sizeOfElement, &bufferSize)) {
    // Handle integer overflow error
    return;
}
...
void* buffer = malloc(bufferSize);
if (!buffer) {
    // Handle memory allocation error
    return;
}

By adding this check, developers can ensure that integer overflow is prevented and mitigate the risk associated with CVE-2023-5849.

Impact and Exploitation

The most significant impact of this exploit involves the potential manipulation of heap corruption that remote attackers can employ via maliciously designed HTML pages. Ultimately, the exploit compromises the target system's stability, security, and user privacy. Heap corruption could allow unauthorized code execution, denial of service attacks, or the disclosure of sensitive information.

Moreover, the Chromium security team has declared the severity of this vulnerability as "High."

Mitigation and Prevention

To protect users and systems from the CVE-2023-5849 vulnerability, upgrading Google Chrome to version 119..6045.105 or later is highly advised.

Developers using the WebUSB API should pay particular attention to properly handling integer overflows in their code, as demonstrated in the aforementioned code snippet.

For full details on CVE-2023-5849, refer to these resources

- Chromium Bug Tracker
- NVD - CVE-2023-5849
- Google Chrome Releases Blog

Timeline

Published on: 11/01/2023 18:15:10 UTC
Last modified on: 11/25/2023 11:15:23 UTC