GHSA-fx2c-96vj-985v HAProxyMessageDecoder Stack Exhaustion DoS

• Maven io.netty:netty-codec-haproxy: < 4.1.86.Final → fixed in 4.1.86.Final

Impact A StackOverflowError can be raised when parsing a malformed crafted message due to an infinite recursion. Patches Users should upgrade to 4.1.86.Final. Workarounds There is no workaround, except using a custom HaProxyMessageDecoder. References When parsing a TLV with type = PP2_TYPE_SSL, the value can be again a TLV with type = PP2_TYPE_SSL and so on. The only limitation of the recursion is that the TLV length cannot be bigger than 0xffff because it is encoded in an unsigned short type. Providing a TLV with a nesting level that is large enough will lead to raising of a StackOverflowError. The StackOverflowError will be caught if HAProxyMessageDecoder is used as part of Netty’s ChannelPipeline, but using it directly without the ChannelPipeline will lead to a thrown exception / crash. For more information If you have any questions or comments about this advisory: • Open an issue in netty