The Heartbleed Bug was a severe security vulnerability in the OpenSSL library that was publicly disclosed in April 2014. OpenSSL is a widely-used open-source implementation of SSL/TLS protocols used for encrypting data transmissions over the internet.

The Heartbleed Bug allowed an attacker to retrieve sensitive information from a server's memory by sending specially crafted requests to a server using OpenSSL. This information could include private keys, user login credentials, and other sensitive data. The severity of the vulnerability lay in its ability to allow an attacker to intercept sensitive information unnoticed and without leaving a trace.

The security flaw was quickly publicized, and developers worked to patch OpenSSL to address the Heartbleed Bug. Website operators and service providers were urged to update their systems and reissue certificates to ensure the security of their data and that of their users.

Heartbleed underscores the potential risks posed by security vulnerabilities in critical open-source software projects and highlights the importance of swift responses and updates to ensure internet security.

BEAST (Browser Exploit Against SSL/TLS) was a security vulnerability discovered in September 2011. This vulnerability primarily affected the TLS (Transport Layer Security) protocol, specifically the Cipher Block Chaining (CBC) encryption mode in conjunction with the SSLv3 and TLS 1.0 protocols.

BEAST allowed an attacker to eavesdrop on and decrypt encrypted traffic between a web browser and a server. This was achieved by exploiting a weakness in the way CBC encryption was implemented in SSL/TLS.

To protect against BEAST attacks, it was recommended to upgrade to newer versions of TLS and to use alternative encryption methods that were not vulnerable to this weakness. Many web servers and browsers also implemented patches to mitigate the impact of BEAST.

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.