issue 2550690 - Adding anti-csrf measures to roundup following https://www.owasp.org/index.php/Cross-Site_Request_Forgery_(CSRF)_Prevention_Cheat_Sheet and https://seclab.stanford.edu/websec/csrf/csrf.pdf Basically implement Synchronizer (CSRF) Tokens per form on a page. Single use (destroyed once used). Random input data for the token includes: system random implementation in python using /dev/urandom (fallback to random based on timestamp as the seed. Not as good, but should be ok for the short lifetime of the token??) the id (in cpython it's the memory address) of the object requesting a token. In theory this depends on memory layout, the history of the process (how many previous objects have been allocated from the heap etc.) I claim without any proof that for long running processes this is another source of randomness. For short running processes with little activity it could be guessed. last the floating point time.time() value is added. This may only have 1 second resolution so may be guessable. Hopefully for a short lived (2 week by default) token this is sufficient. Also in the current implementation the user is notified when validation fails and is told why. This allows the roundup admin to find the log entry (at error level) and try to resolve the issue. In the future user notification may change but for now this is probably best.

--- a/CHANGES.txt	Sat Mar 18 15:12:39 2017 -0400
+++ b/CHANGES.txt	Sat Mar 18 16:59:01 2017 -0400
@@ -178,8 +178,16 @@
   be deprecated. See ``upgrading.txt`` for details.
 - New property for permissions added to simplify the model. See
   ``customizing.txt`` and search for props_only and
-    set_props_only_default in the section 'Adding a new Permission'.
-    (John Rouillard)
+  set_props_only_default in the section 'Adding a new Permission'.
+  (John Rouillard)
+- issue2550690 - Inadequate CSRF protection. Improvements in
+  Cross Site Request Forgery protection to check HTTP headers
+  and nonces. If the header/nonce is present, they are
+  validated. But if headers or nonces are missing access is
+  granted. The enforcement policy can be set in config.ini.
+  Requiring enforcement will need some changes to
+  templates. Support for protecting xmlrpc endpoint not well
+  tested.  See ``upgrading.txt``. (John Rouillard)
 
 Fixed: