- From: Mark Nottingham <mnot@mnot.net>
- Date: Fri, 21 Dec 2018 13:40:11 +1100
- To: Eric Rescorla <ekr@rtfm.com>
- Cc: The IESG <iesg@ietf.org>, draft-ietf-httpbis-cdn-loop@ietf.org, httpbis-chairs@ietf.org, HTTP Working Group <ietf-http-wg@w3.org>, Tommy Pauly <tpauly@apple.com>, Patrick McManus <mcmanus@ducksong.com>
> On 21 Dec 2018, at 12:13 pm, Mark Nottingham <mnot@mnot.net> wrote: > >> We have a situation with two alternate topologies: >> >> 1. A -> B -> Origin >> 2. A -> Origin >> >> The original HTTP client (i.e., an external attacker on the Internet) sends a request with a CDN-Loop header containing B. In topology (1) this causes some kind of failure and in topology (2) it does not, thus leaking the topology. > > Ah - so you're saying that 'A' is also a CDN, not the user-agent? > > If the answer is 'yes', I understand; will add some text. I've added: """ A CDN's use of the CDN-Loop header field might expose its presence. For example, if CDN A is configured to forward its requests to CDN B for a given origin, CDN B's presence can be revealed if it behaves differently based upon the presence of the CDN-Loop header field. """ -- Mark Nottingham https://www.mnot.net/
Received on Friday, 21 December 2018 02:40:41 UTC