Downgrading to Java 8 can also solve Spring Framework RCE

Yesterday we announced a Spring Framework RCE vulnerability CVE-2022-22965, listing Apache Tomcat as one of several preconditions. The Apache Tomcat team has since released versions 10.0.20 , 9.0.62 , and 8.5.78 all of which close the attack vector on Tomcat’s side. While the vulnerability is not in Tomcat itself, in real world situations, it is important to be able to choose among multiple upgrade paths that in turn provides flexibility and layered protection.

Upgrading to Spring Framework 5.3.18+ or 5.2.20+ continues to be our main recommendation not only because it addresses the root cause and prevents other possible attack vectors, but also because it adds protection for other CVEs addressed since the current version in use.

For older, unsupported versions of the Spring Framework, the Tomcat releases provide an adequate solution for the reported attack vector. Nevertheless, we must stress that this should only be seen as a tactical solution that we recommend using in addition to the suggested workaround for double protection against other, not yet known, attack vectors. The main goal should be to upgrade to a currently supported Spring Framework version.

Last but not least, it’s worth mentioning that downgrading to Java 8 provides another viable workaround, which may be a quick and simple thing to do as a tactical solution.

Reference https://spring.io/blog/2022/04/01/spring-framework-rce-mitigation-alternative