Apache Traffic Server forwards malformed HTTP chunked trailer section to origin servers. This can be utilized for request smuggling and may also lead cache poisoning if the origin servers are vulnerable. This issue affects Apache Traffic Server: from 8.0.0 through 8.1.10, from 9.0.0 through 9.2.4. Users can set a new setting (proxy.config.http.drop_chunked_trailers) not to forward chunked trailer section. Users are recommended to upgrade to version 8.1.11 or 9.2.5, which fixes the issue.
https://lists.apache.org/thread/c4mcmpblgl8kkmyt56t23543gp8v56m0