A stack-based buffer overflow vulnerability has been discovered in the libfreeimage library, affecting versions 3.4. through 3.18.. This vulnerability has been assigned CVE-2024-31570. The issue exists in the Load() function of PluginXPM.cpp when handling XPM files, potentially allowing an attacker to execute arbitrary code. In this post, we will dive into the details of the vulnerability, discuss its implications, and provide code snippets from the affected source file.

Background on libfreeimage & CVE-2024-31570

FreeImage is an open-source library that provides support for popular graphics formats and allows developers to create software dealing with image processing, editing, and conversion. It has a wide range of applications and supports multiple platforms, including Windows, macOS, and Linux.

The vulnerability discussed in this post (CVE-2024-31570) is a stack-based buffer overflow that occurs when processing XPM (X PixMap) image files. XPM is an ASCII-based image format used primarily for creating icons, and it is supported by the libfreeimage library.

The flaw exists in the Load() function within the PluginXPM.cpp file. An attacker can exploit this vulnerability by providing a specially crafted malicious XPM file to an application that relies on the libfreeimage library. The attacker can then cause a buffer overflow on the stack, potentially leading to arbitrary code execution, denial of service, or other security implications.

Details of the Vulnerability & Code Snippet

The vulnerability exists in the Load function of PluginXPM.cpp. The issue arises from the incorrect handling of an XPM file's width and height parameters.

Let's analyze the code snippet

BOOL DLL_CALLCONV Load(FreeImageIO *io, fi_handle handle, int page, int flags, void *data) {
    ...
    // Read width, height, color count, and characters per pixel from the input file
    io->read_proc(dummy, 1, 80, handle);
    sscanf(dummy, "%d %d %d %d", &width, &height, &ncolors, &cpp);
    ...
}

As you can see, the function reads the width, height, color count, and characters per pixel (cpp) from the input file and stores them into integer variables. However, there is no proper input validation to ensure that these values are within a safe range. This can lead to a stack-based buffer overflow when processing the XPM file data.

For more details and the original report, please refer to the CVE-2024-31570 entry in the CVE database: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-31570

Exploit Details

An attacker can exploit this vulnerability by crafting a malicious XPM file containing a large width and height parameter. When the affected libfreeimage library processes this file, a buffer overflow will occur on the stack, potentially leading to arbitrary code execution and compromising the security of the affected application.

It is important to note that the attack vector depends on the specific application utilizing the libfreeimage library, which may vary in terms of usage, input processing, and possible mitigations.

Conclusion and Recommendations

The CVE-2024-31570 vulnerability poses a significant risk to applications that rely on the libfreeimage library for processing XPM files. Developers should update their libfreeimage library to the latest version and ensure proper input validation to mitigate the risk of exploitation.

Furthermore, users of applications relying on the libfreeimage library should be cautious when opening XPM files from untrusted sources, as it may lead to arbitrary code execution or potential security breaches.

Timeline

Published on: 09/19/2024 17:15:12 UTC
Last modified on: 09/25/2024 14:57:47 UTC