A new vulnerability has been discovered in Lodepng version v20220717, a popular lightweight PNG encoder and decoder library. This vulnerability, registered as CVE-2022-44081, can lead to a segmentation fault when using the pngdetail() function, resulting in Denial of Service (DoS) attacks and potential memory exploits. In this post, we will provide an in-depth explanation of the vulnerability, its impact, the affected code, and a detailed description of the exploit.

CVE-2022-44081 Vulnerability Details

The CVE-2022-44081 vulnerability exists due to improper input validation in the pngdetail() function, which causes a segmentation fault when processing a corrupted or specifically crafted PNG file. An attacker can exploit this vulnerability to cause a Denial of Service (DoS) attack, potentially affecting the availability, confidentiality, and integrity of the system or services using the Lodepng library.

Affected Code

The vulnerability exists in the pngdetail() function of the Lodepng library. Here's a code snippet from the function that demonstrates the vulnerable code:

void pngdetail(const unsigned char* data, size_t size) {
  lodepng::State state;
  unsigned w, h;
  unsigned error = lodepng_inspect(&w, &h, &state, data, size);
  if (error) {
    std::cout << "error " << error << ": " << lodepng_error_text(error) << std::endl;
  std::vector<unsigned char> buffer(w * h * 4);
  error = lodepng::decode(buffer, w, h, state, data, size);
  if (error) {
    std::cout << "error " << error << ": " << lodepng_error_text(error) << std::endl;

Exploit Details

An attacker can craft a malicious PNG file to take advantage of the CVE-2022-44081 vulnerability. This can be done by creating a PNG file with a specific sequence of bytes that would cause the Lodepng library to treat it as a valid file but would lead to a segmentation fault when processed by the pngdetail() function.

Upon feeding the crafted PNG file to an application or service using Lodepng, the program would experience a segmentation fault and crash. Depending on how the application is designed and implemented, this vulnerability could potentially be exploited to execute arbitrary code, perform memory exploitation, or disrupt the operation of the affected service.

Mitigation and Prevention

The Lodepng developers have been notified of the issue, and a patch is expected to be released soon. In the meantime, it is essential for affected users to exercise caution and avoid processing untrusted PNG files using the pngdetail() function until a fix is available.

In general, it's good practice to implement proper input validation and robust error handling in any application dealing with potentially untrusted data. This helps prevent input from being used in ways that were not intended and can mitigate potential risks from such vulnerabilities and exploits.

Original References

For more information on the Lodepng v20220717 vulnerability (CVE-2022-44081) and other related advisories, please refer to the following links:

1. National Vulnerability Database (NVD) Entry: CVE-2022-44081
2. Lodepng GitHub Repository


The CVE-2022-44081 vulnerability in the Lodepng library (version v20220717) can lead to segmentation faults, causing Denial of Service (DoS) attacks and potential memory exploits. It is crucial to monitor announcements from the Lodepng developers and apply security patches as soon as they become available. Additionally, implementing secure coding practices, such as proper input validation and error handling, can help mitigate risks associated with untrusted data and protect systems against exploitation.


Published on: 10/31/2022 19:15:00 UTC
Last modified on: 11/01/2022 18:09:00 UTC