CVE-2023-40826: Remote Code Execution and Information Disclosure Vulnerability in pf4j v.3.9. and Earlier Versions

A newly discovered vulnerability, tracked as CVE-2023-40826, has been identified in the pf4j library, which stands for Plugin Framework for Java. The affected versions are pf4j v.3.9. and earlier. A remote attacker could exploit this vulnerability to obtain sensitive information from the targeted system and execute arbitrary code.

This blog post aims to provide a detailed explanation of the vulnerability, how it could be exploited, as well as mitigation measures to protect your applications that may be using the pf4j library.

Vulnerability Details

pf4j is a popular open-source library used for creating Java applications with a plugin-based architecture. The vulnerability exists in the way pf4j handles the loading of plugin zip files through the ZipPluginLoader class. A remote attacker can manipulate the zipPluginPath parameter, leading to unauthorized access to sensitive information and arbitrary code execution on the targeted system.

The issue has been assigned CVE-2023-40826 with a CVSS score of 8.8 (High).

Exploitation

The vulnerable code snippet from pf4j's ZipPluginLoader class handling the plugin zip file extraction looks like the following:

File pluginZip = new File(zipPluginPath);
try (ZipFile zipFile = new ZipFile(pluginZip)) {
    // process plugin zip file
}

By manipulating the zipPluginPath parameter, a remote attacker can trick the pf4j library into processing an arbitrary zip file located anywhere on the targeted system. As a result, the attacker can access sensitive information and execute arbitrary code.

To exploit the vulnerability, an attacker could do the following

1. Upload the malicious plugin zip file containing the arbitrary code or sensitive information to a publicly accessible location.
2. Send a request containing the manipulated zipPluginPath parameter pointing to the uploaded malicious zip file.
3. The pf4j library processes the zip file, leading to unauthorized access to sensitive information and arbitrary code execution.

Mitigation Measures

To mitigate this vulnerability and protect your applications, it is strongly recommended to update the pf4j library to the latest version (v4.x or newer), which contains the necessary security patches to address the issue.

You can download the latest pf4j library from the following link: https://github.com/pf4j/pf4j/releases

For projects relying on Maven or Gradle, you can update the pf4j dependency in your pom.xml or build.gradle file, respectively. Make sure to use a version number higher than 3.9.:

<!-- Maven -->
<dependency>
  <groupId>org.pf4j</groupId>
  <artifactId>pf4j</artifactId>
  <version>4.x</version>
</dependency>

// Gradle
dependencies {
    implementation 'org.pf4j:pf4j:4.x'
}

In addition to updating the library, you should review your application code to ensure that any user-supplied input used as zipPluginPath is properly validated and sanitized.

Conclusion

CVE-2023-40826 is a serious vulnerability affecting pf4j library v3.9. and earlier versions, which can lead to unauthorized information disclosure and remote code execution on affected systems. To protect your applications, update the pf4j library to the latest version, and ensure that user input is properly validated.

Stay informed about this vulnerability and others like it by keeping an eye on security advisories, forums, and mailing lists related to pf4j and other libraries your applications rely on.

Timeline

Published on: 08/28/2023 22:15:09 UTC
Last modified on: 08/29/2023 23:53:39 UTC