CVE-2022-41881

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 = PP2TYPESSL, the value can be again a TLV with type = PP2TYPESSL 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.

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For more information

If you have any questions or comments about this advisory:

• Open an issue in netty