Three Google researchers have uncovered a security bug in widely used Internet encryption technology that they say could allow hackers to take over accounts for email, banking and other services in what they have dubbed a "Poodle" attack.

The discovery of Poodle, whose name stands for "padding Oracle on downloaded legacy encryption," prompted makers of web browsers and server software to advise users on Tuesday to disable use of the source of the security bug: an 18-year old encryption standard known as SSL 3.0.

It was the third time this year that researchers have uncovered a vulnerability in widely used web technology, following April's "Heartbleed" bug in OpenSSL and last month's "Shellshock" bug in a piece of Unix software known as Bash.