Understanding CVE-2020-9484: A Critical Vulnerability in Apache Tomcat

Welcome to our insightful article on CVE-2020-9484, a serious vulnerability identified in Apache Tomcat. As cybersecurity enthusiasts and experts in Linux system security, we aim to provide you with a comprehensive understanding of this issue, how it impacts your systems, and crucial steps for mitigation.

What is Apache Tomalice%E2%80%99s dangerous journey Cat?

Apache Tomcat is a widely used open-source web server and servlet container developed by the Apache Software Foundation. It powers a large number of applications across the Internet, making it a critical component of the modern web infrastructure. Tomcat implements several Java EE specifications including Java Servlet, JavaServer Pages (JSP), Java EL, and WebSocket, and provides a "pure Java" HTTP web server environment for Java code to run.

Details of CVE-2020-9484

The CVE-2020-9484 vulnerability impacts various versions of Apache Tomcat. Specifically, it affects versions from 10.0.0-M1 to 10.0.0-M4, 9.0.0.M1 to 9.0.34, 8.5.0 to 8.5.54, and 7.0.0 to 7.0.103. This vulnerability is serious due to its ability to allow attackers to execute code remotely on a server.

The flaw exists because of how Apache Tomcat handles file serialization and deserialization under specific configurations. If the following conditions are met, an attacker can exploit this vulnerability:

  • The attacker has control over the contents and name of a file on the server.
  • The server uses PersistenceManager with a FileStore.
  • PersistenceManager is configured with 'sessionAttributeValueClassNameFilter="null"' or a permissive filter allowing malicious objects' deserialization.
  • The attacker knows the relative file path from the storage location utilized by FileStore to the compromised file.

This vulnerability enables attackers to introduce harmful objects into a system, which are deserialized to execute potentially malicious code remotely. This causes a significant security threat, allowing unauthorized access and control over the affected server.

How to Mitigate CVE-2020-9484

To safeguard your servers from CVE-2020-9484, it is essential to implement the following measures:

  • Upgrade to the latest version of Apache Tomcat that addresses this vulnerability. For each affected version range, a fixed version has been released.
  • Ensure that any use of PersistenceManager with FileStore strictly limits what can be serialized and deserialized.
  • Implement appropriate security measures such as regular updates, secure configuration practices, and proactive monitoring.

Staying vigilant against such vulnerabilities plays a crucial role in cybersecurity. Regular updates and patches are essential in protecting systems from potential threats.

Need More Information?

If you're looking for more detailed guidance or need assistance with securing your systems, visit our website at LinuxPatch. Our platform offers robust patch management solutions tailored for Linux servers, ensuring your systems stay protected against vulnerabilities like CVE-2020-9484.