CVE-2023-38697

protocol-http1 provides a low-level implementation of the HTTP/1 protocol.
RFC 9112 Section 7.1 defined the format of chunk size, chunk data and chunk
extension. The value of Content-Length header should be a string of 0-9
digits, the chunk size should be a string of hex digits and should split
from chunk data using CRLF, and the chunk extension shouldn’t contain any
invisible character. However, Falcon has following behaviors while disobey
the corresponding RFCs: accepting Content-Length header values that have
+ prefix, accepting Content-Length header values that written in
hexadecimal with 0x prefix, accepting 0x and + prefixed chunk size,
and accepting LF in chunk extension. This behavior can lead to desync when
forwarding through multiple HTTP parsers, potentially results in HTTP
request smuggling and firewall bypassing. This issue is fixed in
protocol-http1 v0.15.1. There are no known workarounds.