TE-NULL

Test IDSMUG-TE-NULL
CategorySmuggling
RFCRFC 9110 §5.5, RFC 9112 §6.1
RequirementMUST reject malformed field value
Expected400 or close

What it sends

Transfer-Encoding: chunked<NUL> with Content-Length present.

POST / HTTP/1.1\r\n
Host: localhost:8080\r\n
Transfer-Encoding: chunked\x00\r\n
Content-Length: 5\r\n
\r\n
hello

Why it matters

NUL handling differences (truncate vs reject) are a classic parser differential that can destabilize message framing.

Sources