GHSA-v74w-7mr3-4qg3 Netty: Denial of Service in XmlFrameDecoder via CPU Exhaustion

• Maven io.netty:netty-codec-xml: >= 4.2.0.Final, < 4.2.16.Final → fixed in 4.2.16.Final • Maven io.netty:netty-codec-xml: < 4.1.136.Final → fixed in 4.1.136.Final

Summary An attacker can cause Denial of Service by sending a specially crafted malicious XML payload (e.g., repeated ``. Because the parser state is not saved between `decode()` invocations, an attacker can trickle-feed a payload of `</` characters. This forces the decoder to repeatedly rescan the entire accumulated buffer. A 1MB `maxFrameLength` is enough to completely hang a server's thread while it loops endlessly. Impact Denial of Service via CPU Exhaustion. Any application utilizing Netty's XmlFrameDecoder is impacted. An unauthenticated remote attacker can exploit this flaw by sending a modest amount of malformed XML data to an exposed port.