A newly discovered heap-based buffer overflow vulnerability, identified as CVE-2023-3745, has been found in ImageMagick, a popular software suite used to create, edit, and manipulate image files. This vulnerability resides in the PushCharPixel() function within the quantum-private.h file, which is responsible for pushing a character pixel on the image.

If successfully exploited, this vulnerability could allow a local attacker to cause an application to crash, resulting in a denial of service (DoS). This could be achieved by enticing the user to open a specially crafted malicious file. In this post, we will discuss the specifics of this vulnerability, provide a code snippet demonstrating the issue, share the original references, and explore the potential exploit details.

Vulnerability Details

The CVE-2023-3745 vulnerability stems from a heap-based buffer overflow issue found in ImageMagick's PushCharPixel() function in quantum-private.h. The issue occurs when an out-of-bounds read error is triggered while processing a character pixel in an image file.

Here is the code snippet of PushCharPixel() function in ImageMagick, where the vulnerability lies

static inline void PushCharPixel(CharPixel *p,char c)

As one can see, the function takes a character pixel (char c) and pushes it onto the ImageMagick object without properly validating the size or boundaries of the pixel. This lack of validation can ultimately result in an out-of-bounds read error while processing a malicious image file, leading to a heap-based buffer overflow.


The vulnerability details and impact were initially reported by the ImageMagick team and can be found in their security advisory here:

- ImageMagick Security Advisory: CVE-2023-3745

Additionally, a detailed analysis of the vulnerability, along with a proposed patch, can be found on the ImageMagick GitHub repository issue page:

- ImageMagick GitHub Issue: CVE-2023-3745 Heap-based Buffer Overflow

Exploit Details

A local attacker can exploit this vulnerability by creating a specifically crafted image file, which, when processed by a vulnerable ImageMagick implementation, will cause an out-of-bounds read error. This can result in the application crashing and a subsequent denial of service (DoS) for the end user.

To exploit this vulnerability, an attacker would need to have local access to the targeted system and have the ability to convince the user to open the malicious file. This could be done through various social engineering techniques, such as sending phishing emails or hosting the malicious files on websites.

Upon successfully exploiting the vulnerability, the attacker could cause the application to crash, resulting in a DoS for the end user. While there is no direct information or public exploits demonstrating the ability to execute arbitrary code or perform other attacks based on this vulnerability, further research and analysis might reveal additional impact and potential attack vectors.


The CVE-2023-3745 vulnerability in ImageMagick's PushCharPixel() function highlights the importance of proper input validation and boundary checking while processing user-supplied data, such as image files. As demonstrated in this post, improper handling of character pixels can result in heap-based buffer overflow issues, potentially allowing attackers to crash applications and cause denial of service.

To protect against this vulnerability, users should ensure that they are using the latest version of ImageMagick and apply any available patches or updates. Additionally, users should exercise caution when opening image files from unknown sources, and organizations should educate their users about the potential risks associated with malicious file downloads and social engineering attacks.

By staying informed about these types of vulnerabilities and taking the necessary steps to protect their systems, users can significantly decrease the likelihood of falling victim to a successful exploit or attack.


Published on: 07/24/2023 16:15:00 UTC
Last modified on: 08/02/2023 14:08:00 UTC