Spring4Shell is a critical vulnerability affecting the widely used Java Spring Framework, which emerged in March 2022 and poses significant risks to applications due to its high CVSS rating of 9.8. This vulnerability, specifically CVE-2022-22965, allows remote code execution by exposing the class object in affected applications, particularly those running on Apache Tomcat servers. Attackers can exploit this by executing arbitrary code, posing a severe threat to the security of Java applications. To mitigate this issue, developers are advised to upgrade to non-vulnerable versions of Spring and Apache Tomcat, or adapt application configurations to block exploit attempts. Additionally, Dynatrace Application Security offers real-time detection and blocking of such vulnerabilities through command injection attack prevention, providing a proactive approach to safeguarding systems against Spring4Shell and similar threats. The widespread use of the Spring Framework means many web applications are at risk, highlighting the importance of prompt detection and remediation strategies.