nspluginwrapper forwards variable values requested via NPN_GetValue from firefox to the plugins it wraps around. One of the variables, NPNVprivateModeBool, is used to tell the plugin if firefox is in private browsing mode. The flash plugin (when it is wrapped by nspluginwrapper) queries the browser via nsplugin wrapper and changes its behaviour accordingly. However, the nspluginwrapper versions in RHEL-5 and RHEL-6 do not implement this variable and simply return an error: *** NSPlugin Viewer *** WARNING: unhandled variable 18 (<unknown variable>) in NPN_GetValue() where the enum 18 is NPNVprivateModeBool. As a result, the flash player may continue to run as if the browser is not in private mode. The fix for this issue can be found here: https://github.com/davidben/nspluginwrapper/commit/7e4ab8e1189846041f955e6c83f72bc1624e7a98
Yeah, that's for me.
The Red Hat Security Response Team has rated this issue as having low security impact, a future update may address this flaw.
Raising priority and severity of the case, as we have a customer affected by this issue. Versions of packages used in their environment: firefox-10.0.7-1.el6_3.x86_64 nspluginwrapper-1.3.0-14.el6.x86_64 nspluginwrapper-1.3.0-14.el6.i686 flash-plugin-11.2.202.238-1.el6.i686
This issue has been addressed in following products: Red Hat Enterprise Linux 6 Via RHSA-2012:1459 https://rhn.redhat.com/errata/RHSA-2012-1459.html
Statement: Red Hat Enterprise Linux 5 is now in Production 3 Phase of the support and maintenance life cycle. This has been rated as having Low security impact and is not currently planned to be addressed in future updates. For additional information, refer to the Red Hat Enterprise Linux Life Cycle: https://access.redhat.com/support/policy/updates/errata/.