Zscaler protects against Internet Explorer 0day attack

Today Microsoft released a security advisory (981374) detailing a new, unpatched vulnerability in Internet Explorer (IE), which is currently being used in targeted attacks. While Microsoft has recommended workarounds for this issue, a patch is not yet available and a date has not been set for the release of a patch. Working with Microsoft, through the Microsoft Active Protections Program (MAPP), Zscaler has been provided with confidential data related to this vulnerability, which has been leveraged to deploy protections.

The vulnerability is caused by an invalid pointer reference and impacts IE 6 & 7, while IE 8 is not believed to be vulnerable. All Microsoft recommended workarounds require that client side settings be adjusted and while they make exploitation more complex, do not eliminate the vulnerability. Zscaler was able to deploy protections for this issue throughout its global cloud infrastructure within an hour of receiving notification from Microsoft.

“In our Q4 2009 – State of the Web Report, we detailed that 70% of corporate users on the web are still using Internet Explorer 6 or 7, all of which are now vulnerable to attack”, according to Michael Sutton, VP, Security Research at Zscaler. “While adoption on Internet Explorer 8 has been relatively brisk among consumers, enterprises have been far slower to adopt new browser technology. Vulnerabilities such as the one disclosed today illustrate why supported software is not secure software. Enterprises should revisit their decision to delay the deployment of Internet Explorer 8.”

Zscaler customers are currently protected from this vulnerability (CVE-2010-0806) without the need to make any policy changes. Zscaler will continue to monitor for active exploitation of this issue and will release further reports as the situation warrants.