Google patches critical Windows bugs, updates Mac Chrome beta

Google updated the Mac beta of its Chrome browser, adding the support for extensions that had previously been available only in a less stable "developer" build.

Also now part of Mac Chrome's beta are bookmark synchronisation, improved bookmark and cookie managers, and a task manager for handling the browser's tabs. The latter is useful since Chrome - unlike most rivals - runs each tab as a separate process to prevent browser crashes when one tab stalls. The task manager can be used to monitor Chrome's memory usage - the each-tab-in-its-own-process approach consumes prodigious amounts of memory - and kill a tab if it's unresponsive.

Google first added extension support and bookmark synchronisation to a "dev" channel Mac edition of Chrome in early January. Before that, Chrome for the Mac had lacked important features, including extensions and sync, that were already available in the Windows and Linux editions.

Today's update was to version 5.0.307.7; current Chrome users can wait for the automatic update, which should kick in within the next 24 hours, or if impatient, can select "About Google Chrome" from the browser's "Chrome" menu to check for and then download available updates.

Yesterday, Google patched seven security vulnerabilities in the production edition of Chrome for Windows. Google ranked three of the bugs as "high" in its severity scoring system. Access to information on those three flaws, as well as on one tagged "medium," have been blocked by Google, which regularly locks down details until it decides that a majority of Chrome users have upgraded to the patched version.

One of the four blocked bugs - the one marked medium - is the first that got its finder a cash prize from Google's new bug bounty programme. Google awarded researcher Timothy Morgan $500 to inaugurate the Chromium Security Reward program, but then bumped that up to the maximum of $1,337 when Morgan said he wanted to donate the original bounty to the Haitian earthquake relief effort, said Anthony Laforge, a Chrome program manager.

Danish vulnerability tracker Secunia rated the just-patched Windows Chrome bugs as "highly critical," its second-most-serious threat ranking.

Chrome is used by about 5% of the world's browsing population, according to data from Web metrics firm NetApplications.com. By comparison, Microsoft's Internet Explorer and Mozilla's Firefox control 62% and 24% of the browser market, respectively.

The beta of Chrome for the Mac can be downloaded from Google's Web site. It requires Mac OS X 10.5 (aka Leopard) or later, and runs only on Macs powered by Intel processors.