The PepperFlashRendererHost::OnNavigate function in renderer/pepper/pepper_flash_renderer_host.cc in Google Chrome before 33.0.1750.146 does not verify that all headers are Cross-Origin Resource Sharing (CORS) simple headers before proceeding with a PPB_Flash.Navigate operation, which might allow remote attackers to bypass intended CORS restrictions via an inappropriate header.
https://src.chromium.org/viewvc/chrome?revision=249114&view=revision
https://code.google.com/p/chromium/issues/detail?id=332023
http://www.securityfocus.com/bid/65930
http://www.debian.org/security/2014/dsa-2883
http://googlechromereleases.blogspot.com/2014/03/stable-channel-update.html