Microsoft released a Fix It tool today to allow customers to disable SSL 3.0 in all supported versions of Internet Explorer in light of a recently revealed vulnerability affecting the protocol.
Microsoft also announced it will be working to disable fallback to SSL 3.0 and disable SSL 3.0 by default in Internet Explorer (IE) and Microsoft online services during the coming months.
"Millions of people and thousands of organizations around the world rely on our products and services every day, and while the number of systems that rely on SSL 3.0 exclusively is very small, we recognize that, particularly for enterprises, disabling the protocol may cause some impact," blogged Tracey Pretorius, director of communications for Microsoft's Security Response Center. "That’s why we’re taking a planned approach to this issue and providing customers with advance notice."
While the security of SSL 3.0 has been dinged in the past, it came into the spotlight earlier this month with the revelation of the Poodle (Padding Oracle On Downgraded Legacy Encryption) attack. The vulnerability allows a man-in-the-middle attacker to decrypt secure HTTP cookies.
According to Microsoft, starting Dec. 1, Office 365 and Azure will begin disabling support for SSL 3.0. In addition, all client/browser combinations will need to utilize TLS 1.0 or higher to connect to Azure and Office 365 services without issues. This may require certain client/browser combinations to be updated, Microsoft noted.
"If you are currently using older versions of IE, such as IE 6, we recommend you upgrade to a newer browser as soon as possible, in addition to using the Fix it released today," Pretorius blogged. "IE 11 is our latest and most secure browser and customers who upgrade will continue to benefit from additional security features."