GHSA-v74w-7mr3-4qg3
Netty: Denial of Service in XmlFrameDecoder via CPU Exhaustion
Quick fix
GHSA-v74w-7mr3-4qg3 — io.netty:netty-codec-xml: upgrade to the fixed version with the command below.
# pom.xml: bump <version>4.2.16.Final</version> for io.netty:netty-codec-xml Details
### Summary An attacker can cause Denial of Service by sending a specially crafted malicious XML payload (e.g., repeated `</` characters) to a Netty server utilizing XmlFrameDecoder, causing the server's EventLoop thread to exhaust CPU resources and become unresponsive.
### Details `io.netty.handler.codec.xml.XmlFrameDecoder` suffers from a vulnerability resulting in CPU exhaustion. When `<` followed by `/` is encountered, the decoder scans the remaining buffer for a closing `>`. 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.
Are you affected?
Enter the version of the package you're using.
Affected packages
4.2.0.Final Fixed in: 4.2.16.Final # pom.xml: bump <version>4.2.16.Final</version> for io.netty:netty-codec-xml 0 Fixed in: 4.1.136.Final # pom.xml: bump <version>4.1.136.Final</version> for io.netty:netty-codec-xml References
- https://github.com/netty/netty/security/advisories/GHSA-v74w-7mr3-4qg3 [WEB]
- https://github.com/netty/netty/pull/17063 [WEB]
- https://github.com/netty/netty/pull/17065 [WEB]
- https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003b [WEB]
- https://github.com/netty/netty/commit/bb2ff68a1fb71cb4b0eb9a9e17b66c52aff680c6 [WEB]
- https://github.com/netty/netty [PACKAGE]
- https://github.com/netty/netty/releases/tag/netty-4.1.136.Final [WEB]
- https://github.com/netty/netty/releases/tag/netty-4.2.16.Final [WEB]