Two bugs, one affecting Apple's Mac platform and another attacking Microsoft's Windows, exploit certain Flash player vulnerabilities to install malware onto users' systems, reports ArsTechnica. While users of other operating systems like Linux have yet to report attacks, Adobe's advisory notes the exploit affects all platforms.
Designated as CVE-2013-0634, the first vulnerability targets the Safari and Firefox Web browsers running on OS X, and is also being used as a trojan to deploy Microsoft Word documents containing malware. For Mac users, the flaw affects Adobe Flash Player version 11.5.502.146 or earlier.
On March 1, 2013 Apple again blocked Flash Player for Lion and Mountain Lion:
You should uninstall any previous version first, and repair permissions after installing the new version.
If you still get a ‘plug-ins blocked’ message:
My problem is similar -- youtube videos appear as just an unchanging black square in Firefox. It happened when I updated (or maybe got an automatic update) to Flash 13.x on OS X 10.6.8.
As my iMac is ancient, a 2006 Core Duo, I thought it might be that its 32 bit-ness was forgotten by Adobe. What finally fixed it for me was:
1. Download and run the Flash Uninstaller from:
2. Download and install the latest non 13.x version of Flash (I had luck with 184.108.40.206) from:
You will be prompted to close your browser at least once, so either bookmark this page or restore previous session to not lose these URLs.
I hope this helps.