■■■■■ Zero-Day: Spring Framework RCE, Official Announcement {Spring4Shell}.
The vulnerability impacts Spring MVC and Spring WebFlux applications running on JDK 9+. The specific exploit requires the application to run on Tomcat as a WAR deployment. If the application is deployed as a Spring Boot executable jar, i.e. the default, it is not vulnerable to the exploit. However, the nature of the vulnerability is more general, and there may be other ways to exploit it.
https://spring.io/blog/2022/03/31/spring-framework-rce-early-announcement
https://t.me/cKure/11099