Apache Tapestry uses HMACs to verify the integrity of objects stored on the client side. This was added to address the Java deserialization vulnerability disclosed in CVE-2014-1972. In the fix for the previous vulnerability, the HMACs were compared by string comparison, which is known to be vulnerable to timing attacks.

Affected Versions

  • Apache Tapestry 5.3.6 through current releases.


No new release of Tapestry has occurred since the issue was reported. Affected organizations may want to consider locally applying commit d3928ad44714b949d247af2652c84dae3c27e1b1.


  • 2019-03-12: Issue discovered.
  • 2019-03-13: Issue reported to
  • 2019-03-29: Pinged thread to ask for update.
  • 2019-04-19: Fix committed.
  • 2019-04-23: Asked about release timeline, response “in the upcoming months”
  • 2019-05-28: Pinging again about release.
  • 2019-06-24: Asked again, asked for CVE number assigned. No update on timeline.
  • 2019-08-22: Disclosure posted.


This vulnerability was discovered by David Tomaschik of the Google Security Team.