[] (0) Mention that iframe can be used for probing local network HTTP…

… servers. (This could also be done with other elements, like object, I guess, but I haven't mentioned that here.)

Affected topics: HTML

git-svn-id: http://svn.whatwg.org/webapps@7797 340c8d12-0b0e-0410-8428-c7bf67bfef74

complete.html

@@ -24530,7 +24530,12 @@ <h4 id=the-iframe-element><span class=secno>4.8.2 </span>The <dfn><code>iframe</
    <li><p>Unset <var title="">child document</var>'s <a href=#iframe-load-in-progress>iframe load in progress</a>
    flag.</li>
 
-  </ol><p>When the <code><a href=#the-iframe-element>iframe</a></code>'s <a href=#browsing-context>browsing context</a>'s <a href=#active-document>active document</a> is
+  </ol><p class=warning>This, in conjunction with scriptingy, can be used to probe the URL space of the
+  local network's HTTP servers. User agents may implement <a href=#origin title=origin>cross-origin</a>
+  access control policies that are stricter than those described above to mitigate this attack, but
+  unfortunately such policies are typically not compatible with existing Web content.</p>
+
+  <p>When the <code><a href=#the-iframe-element>iframe</a></code>'s <a href=#browsing-context>browsing context</a>'s <a href=#active-document>active document</a> is
   not <a href=#ready-for-post-load-tasks>ready for post-load tasks</a>, and when anything in the <code><a href=#the-iframe-element>iframe</a></code> is <a href=#delay-the-load-event title="delay the load event">delaying the load event</a> of the <code><a href=#the-iframe-element>iframe</a></code>'s
   <a href=#browsing-context>browsing context</a>'s <a href=#active-document>active document</a>, and when the <code><a href=#the-iframe-element>iframe</a></code>'s
   <a href=#browsing-context>browsing context</a> is in the <a href=#delaying-load-events-mode>delaying <code title=event-load>load</code> events

index

@@ -24530,7 +24530,12 @@ href="?audio"&gt;audio&lt;/a&gt; test instead.)&lt;/p&gt;</pre>
    <li><p>Unset <var title="">child document</var>'s <a href=#iframe-load-in-progress>iframe load in progress</a>
    flag.</li>
 
-  </ol><p>When the <code><a href=#the-iframe-element>iframe</a></code>'s <a href=#browsing-context>browsing context</a>'s <a href=#active-document>active document</a> is
+  </ol><p class=warning>This, in conjunction with scriptingy, can be used to probe the URL space of the
+  local network's HTTP servers. User agents may implement <a href=#origin title=origin>cross-origin</a>
+  access control policies that are stricter than those described above to mitigate this attack, but
+  unfortunately such policies are typically not compatible with existing Web content.</p>
+
+  <p>When the <code><a href=#the-iframe-element>iframe</a></code>'s <a href=#browsing-context>browsing context</a>'s <a href=#active-document>active document</a> is
   not <a href=#ready-for-post-load-tasks>ready for post-load tasks</a>, and when anything in the <code><a href=#the-iframe-element>iframe</a></code> is <a href=#delay-the-load-event title="delay the load event">delaying the load event</a> of the <code><a href=#the-iframe-element>iframe</a></code>'s
   <a href=#browsing-context>browsing context</a>'s <a href=#active-document>active document</a>, and when the <code><a href=#the-iframe-element>iframe</a></code>'s
   <a href=#browsing-context>browsing context</a> is in the <a href=#delaying-load-events-mode>delaying <code title=event-load>load</code> events

source

@@ -25775,6 +25775,11 @@ href="?audio">audio&lt;/a> test instead.)&lt;/p></pre>
 
   </ol>
 
+  <p class="warning">This, in conjunction with scriptingy, can be used to probe the URL space of the
+  local network's HTTP servers. User agents may implement <span title="origin">cross-origin</span>
+  access control policies that are stricter than those described above to mitigate this attack, but
+  unfortunately such policies are typically not compatible with existing Web content.</p>
+
   <p>When the <code>iframe</code>'s <span>browsing context</span>'s <span>active document</span> is
   not <span>ready for post-load tasks</span>, and when anything in the <code>iframe</code> is <span
   title="delay the load event">delaying the load event</span> of the <code>iframe</code>'s