The AppCacheUpdateJob::URLFetcher::OnResponseStarted function in content/browser/appcache/appcache_update_job.cc in Google Chrome before 40.0.2214.91 proceeds with AppCache caching for SSL sessions even if there is an X.509 certificate error, which allows man-in-the-middle attackers to spoof HTML5 application content via a crafted certificate.
https://codereview.chromium.org/725573004
https://codereview.chromium.org/645123003
https://codereview.chromium.org/579593003
https://code.google.com/p/chromium/issues/detail?id=414026
http://www.ubuntu.com/usn/USN-2476-1
http://www.securitytracker.com/id/1031623
http://www.securityfocus.com/bid/72288
http://security.gentoo.org/glsa/glsa-201502-13.xml
http://secunia.com/advisories/62665
http://secunia.com/advisories/62575
http://secunia.com/advisories/62383
http://rhn.redhat.com/errata/RHSA-2015-0093.html
http://lists.opensuse.org/opensuse-security-announce/2015-03/msg00005.html
http://googlechromereleases.blogspot.com/2015/01/stable-update.html