CVE-2023-5474: Heap Buffer Overflow in PDF Renderer in Google Chrome Versions Prior to 118..5993.70 - Vulnerability and Exploit Analysis

Heap buffer overflow vulnerabilities have always been a major concern for software security as they potentially allow attackers to gain unauthorized access, execute arbitrary code, or even crash an application. Recently, a heap buffer overflow vulnerability (CVE-2023-5474) was discovered in the PDF rendering module of Google Chrome versions prior to 118..5993.70. This vulnerability, categorized as having medium severity by Chromium security, allows a malicious actor to potentially exploit heap corruption by convincing a user to engage in specific interactions with a crafted PDF file. In this comprehensive analysis, we will delve into the details of the vulnerability, with code snippets, exploit mechanisms, and original references to help the reader understand the intricacies involved in this security issue.

Vulnerability Details

A heap buffer overflow vulnerability was found in the PDF rendering module of Google Chrome when processing certain content within crafted PDF files. Due to an uncontrolled memory allocation, the application may end up reading more data than it is supposed to, leading to heap corruption. If successfully exploited, this vulnerability could allow an attacker to create a specially crafted PDF file that, upon being opened by the user, could lead to memory corruption and possibly the execution of arbitrary code on the target machine. ])

Code Snippet

The vulnerability can be triggered by manipulating certain properties within a malicious PDF file. A high-level overview of the vulnerable code might look like this:

void process_pdf_content(pdf_content_t *content) {
    size_t size = content->size;
    char *data = malloc(size);
    if (data == NULL) {
        perror("Failed to allocate memory for PDF content");
        return;
    }

    memcpy(data, content->data, size+1); // Overflow occurs here

    ...
}

When processing the PDF content, memory is allocated for the data, but the memcpy function incorrectly copies more bytes than allocated due to the addition of 1, causing the heap buffer overflow.

Exploit Mechanisms

The exploitation of this vulnerability can be achieved by convincing a user to perform specific interactions with a specially crafted PDF file. This can include but is not limited to:

Engaging in certain user interactions such as search, zoom, or scrolling through the PDF file.

As this vulnerability has a medium severity rating, successful exploitation may result in heap corruption, and possibly the execution of arbitrary code or application crash. However, it should be noted that the attacker would require considerable knowledge about the victim's system and memory layout to achieve code execution.

Mitigation

The vulnerability was addressed in Google Chrome version 118..5993.70. Users are urged to update their browsers to the latest version to remain protected from this vulnerability. The patch can be downloaded from the official Google Chrome website (https://www.google.com/chrome/) or through the browser's built-in update mechanism.

Original References

1. The Chromium Projects - Chromium Security Updates
2. The Chromium Projects - Chromium Security
3. The National Vulnerability Database - CVE-2023-5474

Conclusion

CVE-2023-5474, a heap buffer overflow vulnerability in the PDF rendering module of Google Chrome versions prior to 118..5993.70, highlights the importance of secure coding practices and keeping software updated. While rated as medium severity, the ramifications of successful exploitation could still be severe for end-users. Therefore, it is crucial to remain vigilant, apply software updates promptly, and be cautious when engaging with untrusted content.

Timeline

Published on: 10/11/2023 23:15:10 UTC
Last modified on: 10/20/2023 20:18:22 UTC