Original URL: http://www.theregister.co.uk/2013/11/15/blackberry_link_update_addresses_security_bugs/

BlackBerry on the brink: Security kink sinks rinky-dink Link sync in a blink

Update your mobe's desktop software, then have a drink

By Shaun Nichols

Posted in Security, 15th November 2013 11:32 GMT

Hapless BlackBerry has told users to update its software on their Mac OS X and Windows computers following the disclosure of a fairly serious security flaw.

The Canadian handset maker said the vulnerability exists in selected versions of its freely available Link application – a program that allows you to transfer files between your BlackBerry mobes and an Apple or Microsoft-powered computer. Users are urged to upgrade to the latest available builds, which are not vulnerable to the discovered blunder.

The flaw stems from the fact that Link provides access to the user's files via a WebDAV server that can be accessed over the network and yet doesn't perform any authentication checks. This clears the way for an attacker, under certain conditions, to elevate their login privileges and run arbitrary commands by tricking another user into clicking on a specially crafted web link or visiting a malicious web page.

More details on how the WebDAV file server can be exploited remotely can be found here, on the personal blog of Google security researcher Tavis Ormandy, who reported the flaw to BlackBerry. Ollie Whitehouse also separately alerted BlackBerry to the cockup.

BlackBerry said that in addition to updating the Link software to a patched release, users and administrators can apply certain mitigation techniques to guard against exploitation of the flaws. Those tips include removing the remote file sharing directory in Link.

According to recent analyst reports, the number of people who will need to install a Link update could be as low as it has ever been. Researchers at IDC estimated that 1.7 per cent of smartphones sold last quarter ran a BlackBerry OS.

For the admins whose companies who still run the BlackBerry platform, an update for BlackBerry Link will pile on to what has already been a heavy load of security patches this week. Along with Microsoft's Patch Tuesday bundle, Adobe pitched a set of fixes for its ubiquitous Flash Player tool as well as the ColdFusion application server. ®