(CNN) -- A major online security vulnerability dubbed "Heartbleed" could put your personal information at risk, including passwords, credit card information and e-mails.
Heartbleed is a flaw in OpenSSL, an open-source encryption technology that is used by an estimated two-thirds of Web servers. It is behind many HTTPS sites that collect personal or financial information. These sites are typically indicated by a lock icon in the browser to let site visitors know the information they're sending online is hidden from prying eyes.
Cybercriminals could exploit the bug to access visitors' personal data as well as a site's cryptographic keys, which can be used to impersonate that site and collect even more information.
You can use the Heartbleed Test website (http://filippo.io/Heartbleed/) to test your external websites and external-facing web appliances to see if they are vulnerable. I encourage you to make a quick test of your systems ASAP.
If you use Google Chrome, I encourage you to install the Chromebleed plug-in which displays a warning if the site you are browsing is affected by the Heartbleed bug.