Affected: VMware Spring Framework

A WebFlux server application that processes multipart requests creates temp files for parts larger than 10 K. Under some circumstances, temp files may remain not deleted after the request is fully processed. This allows an attacker to consume available disk space.

Older, unsupported versions are also affected.

Affected: Maven: io.netty:netty-codec-http

### Summary Netty incorrectly parses malformed Transfer-Encoding, enabling request smuggling attacks.

### Details Netty incorrectly marks a request as chunked when malformed "Transfer-Encoding: chunked, identity" is present. According to RFC https://datatracker.ietf.org/doc/html/rfc9112#name-message-body-length

" If a Transfer-Encoding header field is present in a request and the chunked transfer coding is not the final encoding, the message body length cannot be determined reliably; the server MUST respond with the 400 (Bad Request) status code and then close the connection. "

A possible scenario is when Netty is behind a proxy that doesn't reject requests with "Transfer-Encoding: chunked, identity", but prefers "Content-Length" and forwards the content to Netty.

### PoC The test below shows Netty successfully parsing the second request, demonstrating how an attacker can smuggle a second request inside a request body.

```java @Test public void test() { String requestStr = "POST / HTTP/1.1\r\n" + "Host: localhost\r\n" + "Transfer-Encoding: chunked, identity\r\n" + "Content-Length: 48\r\n" + "\r\n" + "0\r\n" + "\r\n" + "GET /smuggled HTTP/1.1\r\n" + "Host: localhost\r\n" + "\r\n";

EmbeddedChannel channel = new EmbeddedChannel(new HttpRequestDecoder()); assertTrue(channel.writeInbound(Unpooled.copied…