Discovery of a Game-Changing Exploit

In a world increasingly reliant on digital solutions, security threats are an ever-present danger. Today, the cybersecurity community has issued an urgent warning regarding a critical vulnerability that has been discovered in Apache Tomcat, a widely used web server application. According to TechRadar, this vulnerability can potentially allow cybercriminals to seize full control of your servers with shocking ease. The threat actors can execute this breach with just a single PUT API request.

How Hackers Exploit This Weakness

Wallarm, a leading security outfit, has identified a proof-of-concept (PoC) attack method that abuses a deserialization flaw in Apache Tomcat. The flaw, identified as CVE-2025-24813, relies on uploading a malicious serialized Java session. When Apache Tomcat, utilized in many deployments, retrieves this session, it inadvertently grants attackers full remote access by executing embedded Java code.

Little Barrier for Attackers

This security flaw is particularly alarming due to its ease of execution. As Wallarm highlights, hackers do not require authentication to launch this attack. The only prerequisite is the use of file-based session storage, a common setup among many web applications. The use of base64 encoding enables the attack to slip past traditional security filters, making early detection incredibly challenging and often too late.

Consequences and Industry Response

Once inside, the possibilities for exploitation are vast. This vulnerability allows attackers to upload malicious JSP files, modify configurations, and create backdoors, further exacerbating security risks. Despite its severity, this flaw currently lacks an official severity score. Currently, it affects Apache Tomcat versions from 11.0.0-M1 through 11.0.2, 10.1.0-M1 through 10.1.34, and 9.0.0.M1 through 9.0.98.

Security experts urge all server administrators using affected versions to upgrade immediately to the safe versions: 11.0.3, 10.1.35, or 9.0.98. Swift action is required to prevent potential breaches and safeguard sensitive data.

Act now to protect your systems, or risk being the next statistic in an increasingly dangerous digital landscape. The implications of failing to address this security flaw could be catastrophic, leading to significant data losses and operational disruptions.

Stay vigilant, and ensure that your security teams are updated on the latest patches and security practices to defend against emerging threats.