POODLE (Padding Oracle On Downgraded Legacy Encryption) was a security vulnerability in the SSLv3 (Secure Sockets Layer version 3) encryption protocol, discovered in October 2014. This vulnerability allowed an attacker to eavesdrop on and manipulate encrypted traffic between a web browser and a server. The attack exploited a weakness in the way SSLv3 processed blocks of encrypted data with padding. By exploiting this vulnerability, an attacker could, under certain circumstances, steal sensitive information such as cookies.
Due to the severity of the vulnerability, security experts recommended disabling the use of SSLv3 and upgrading to newer and more secure encryption protocols such as TLS (Transport Layer Security). Many web servers and browsers removed or disabled SSLv3 support to protect against POODLE attacks.
