CHUNK-EXT-CR

Test IDSMUG-CHUNK-EXT-CR
CategorySmuggling
RFCRFC 9112 §7.1.1, RFC 9112 §2.2
RequirementMUST reject malformed chunk line
Expected400 or close

What it sends

A chunk-size line where a bare CR appears inside the extension area, not as a valid CRLF terminator.

POST / HTTP/1.1\r\n
Host: localhost:8080\r\n
Transfer-Encoding: chunked\r\n
\r\n
5;a\rX\r\n
hello\r\n
0\r\n
\r\n

Why it matters

Differential handling of bare CR in framing metadata can produce parser disagreement across hops and create desync risk.

Sources