MEDIUM: mux-h1: Reject HTTP/1.0 GET/HEAD/DELETE requests with a payload

This kind of requests is now forbidden and rejected with a
413-Payload-Too-Large error.

It is unexpected to have a payload for GET/HEAD/DELETE requests. It is
explicitly allowed in HTTP/1.1 even if some servers may reject such
requests. However, HTTP/1.0 is not clear on this point and some old servers
don't expect any payload and never look for body length (via Content-Length
or Transfer-Encoding headers).

It means that some intermediaries may properly handle the payload for
HTTP/1.0 GET/HEAD/DELETE requests, while some others may totally ignore
it. That may lead to security issues because a request smuggling attack is
possible.

To prevent any issue, those requests are now rejected.

See also httpwg/http-core#904
This commit is contained in:
Christopher Faulet 2021-09-21 18:44:55 +02:00
parent b3230f76e8
commit e136bd12a3

View File

@ -1402,6 +1402,24 @@ static size_t h1_handle_headers(struct h1s *h1s, struct h1m *h1m, struct htx *ht
goto end;
}
/* Reject HTTP/1.0 GET/HEAD/DELETE requests with a payload. There is a
* payload if the c-l is not null or the the payload is chunk-encoded.
* A parsing error is reported but a A 413-Payload-Too-Large is returned
* instead of a 400-Bad-Request.
*/
if (!(h1m->flags & (H1_MF_RESP|H1_MF_VER_11)) &&
(((h1m->flags & H1_MF_CLEN) && h1m->body_len) || (h1m->flags & H1_MF_CHNK)) &&
(h1sl.rq.meth == HTTP_METH_GET || h1sl.rq.meth == HTTP_METH_HEAD || h1sl.rq.meth == HTTP_METH_DELETE)) {
h1s->flags |= H1S_F_PARSING_ERROR;
htx->flags |= HTX_FL_PARSING_ERROR;
h1s->h1c->errcode = 413;
TRACE_ERROR("HTTP/1.0 GET/HEAD/DELETE request with a payload forbidden", H1_EV_RX_DATA|H1_EV_RX_HDRS|H1_EV_H1S_ERR, h1s->h1c->conn, h1s);
h1_capture_bad_message(h1s->h1c, h1s, h1m, buf);
ret = 0;
goto end;
}
/* If websocket handshake, search for the websocket key */
if ((h1m->flags & (H1_MF_CONN_UPG|H1_MF_UPG_WEBSOCKET)) ==
(H1_MF_CONN_UPG|H1_MF_UPG_WEBSOCKET)) {