From: William A. Rowe Jr Strict
operating mode.
RFC 7230 §3.5 "Message Parsing Robustness" identify the
+ risks of accepting obscure whitespace and request message formatting.
+ As of the introduction of this directive, all grammer rules of the
+ specification are enforced in the default Strict
operating
+ mode, and the strict whitespace suggested by section 3.5 is enforced
+ and cannot be relaxed.
RFC 3986 §2.2 and 2.3 define "Reserved Characters" and
@@ -1293,21 +1296,9 @@ LenientMethods Allow0.9
containing invalid characters. This rule can be relaxed with the
UnsafeURI
option to support badly written user-agents.
RFC 7230 §3.5 "Message Parsing Robustness" permits, and
- identifies potential risks of parsing messages containing non-space
- character whitespace. While the spec defines that exactly one space
- seperates the URI from the method, and the protocol from the URI, and
- only space and horizontal tab characters are allowed in request header
- field contents, the Apache HTTP Server was traditionally lenient in
- accepting other whitespace. The default StrictWhitespace
- option will now reject non-conforming requests. The administrator may
- toggle the UnsafeWhitespace
option to continue to honor
- non-conforming requests, with considerable risk of proxy interactions.
Users are strongly cautioned against toggling the Unsafe
,
- UnsafeURI
or UnsafeWhitespace
modes of operation
- particularly on outward-facing, publicly accessible server deployments.
+
Users are strongly cautioned against toggling the Unsafe
+ or UnsafeURI
modes of operation, particularly on
+ outward-facing, publicly accessible server deployments.
If an interface is required for faulty monitoring or other custom service
consumers running on an intranet, users should toggle only those Unsafe
options which are necessary, and only on a specific virtual host configured