In this in-depth article, we will discuss the recently identified vulnerability CVE-2023-46154, which affects the popular WordPress plugin, E2Pdf. If you are using E2Pdf – Export To Pdf Tool for WordPress, it is crucial to understand this vulnerability, as the implications may be severe.

E2Pdf is a widely used tool for exporting WordPress posts, pages, and forms to PDF files. It allows users to create customizable PDF templates via a live builder, enabling them to showcase their content in a professional and visually appealing manner. However, researchers have recently discovered a security flaw in versions up to 1.20.18, which allows attackers to execute arbitrary code via 'Deserialization of Untrusted Data.'

The vulnerability is caused by the insecure deserialization of data, which is used within the plugin to read and write data to and from a binary format. We will dive deep into the details of this vulnerability, provide a code snippet to demonstrate the issue, and discuss how to avoid and mitigate the potential risks associated with this vulnerability.

What is Deserialization of Untrusted Data?

In computer programming, serialization is the process of converting complex data structures, such as objects, into a byte stream (a sequence of bytes) that can be easily stored, transmitted, or manipulated. Deserialization is the reverse process, where a byte stream is translated back into a complex data structure such as an object.

In general, deserialization of untrusted data refers to a situation in which an application receives serialized data from an untrusted source and deserializes the data without verifying the legitimacy of the data. This can lead to security issues if an attacker manipulates the serialized data to inject malicious code or gain unauthorized access to the system.

Vulnerability Details (CVE-2023-46154)

CVE-2023-46154 concerns the insecure deserialization of data in E2Pdf – Export To Pdf Tool for WordPress, specifically in versions up to 1.20.18. The vulnerability exists because the plugin fails to adequately validate and sanitize user-provided input when handling serialized data. As a result, remote attackers can execute arbitrary code or manipulate the application in various harmful ways.

Below is a code snippet demonstrating the insecure deserialization of data within the E2Pdf plugin

public function unserialize($file)
  if (file_exists($file)) {
    $data = @file_get_contents($file);
    if ($data) {
      $unserialized_data = @unserialize($data);
      if ($unserialized_data !== false) {

As seen in the code snippet, the unserialize() function reads a file and deserializes its contents without proper sanitation and validation. This opens the door for attackers to exploit the vulnerability by sending a specially crafted payload with malicious code to the unserialize() function.

For reference, a proof-of-concept code exploiting this vulnerability is available on Exploit-DB.

To protect your WordPress website from CVE-2023-46154, employ the following measures

1. Update E2Pdf – Export To Pdf Tool for WordPress to the latest version (greater than 1.20.18). This issue has been addressed in subsequent releases, so upgrading the plugin should resolve the vulnerability.

Regularly check and update all WordPress themes, plugins, and core to keep your site secure.

3. Consider implementing a Web Application Firewall (WAF) to block malicious payloads from reaching your site.

4. Use security best practices when coding, including proper input validation and sanitation, to prevent vulnerabilities such as this one.

In conclusion, as much as E2Pdf – Export To Pdf Tool for WordPress is a powerful and widely used tool for creating PDF content, it is crucial to be aware of potential security flaws such as CVE-2023-46154. By understanding the vulnerability, keeping the plugin updated, and employing security best practices, you can mitigate the risks associated with insecure deserialization and protect your website from potential attacks.


Published on: 12/19/2023 00:15:07 UTC
Last modified on: 12/22/2023 19:39:53 UTC