SAP Netweaver Java has a stack of standard J2EE filters responsible to do some controls and statistical operations over each received request. The vulnerability exists because one of those filters is keeping information about the different HTTP methods received by the server, but it is not properly controlling how much memory it needs to store that information. After sending a specially crafted request, an attacker is able to make that filter raise an OutOfMemoryError, making the virtual machine crash. References: - https://onapsis.com/blog/sap-security-patch-day-july-2021-serious-vulnerabilities-sap-netweaver-java-fixed - Vendor Patch: https://launchpad.support.sap.com/#/notes/3056652