Depth counting error in guard() leading to multiple potential security issues in aioxmpp

Impact Possible remote Denial of Service or Data Injection. Patches Patches are available in https://github.com/horazont/aioxmpp/pull/268. They have been backported to the 0.10 release series and 0.10.3 is the first release to contain the fix. Workarounds To make the bug exploitable, an error...