BEAST
Browser Exploit Against SSL/TLS
Related warning
"The server is vulnerable to the BEAST attack."
Problem
The Browser Exploit Against SSL/TLS (BEAST) attack affects the SSL 2.0, SSL 3.0, and TLS 1.0 protocols. This allows a bad actor to decrypt the contents of an SSL-encrypted or TLS-encrypted session between a web browser and a website. The attacker takes advantage of weakness in the block-based cipher suites.
Note
This is a client-side attack where the attacker needs to control the "victim's" browser. Most browsers are vulnerable to the BEAST attack.
In a BEAST attack, the attacker acts as a man-in-the-middle and uses specially crafted plaintext input to decrypt the contents of an SSL-encrypted or TLS-encrypted session between a web browser and a website. This type of attack allows the attacker to recover sensitive information (e.g., HTTP authentication cookies).
Solution
Enable TLS 1.2 or TLS 1.3 on servers that support these protocols.
Enable TLS 1.2 or TLS 1.3 in web browsers that support these protocols.
Workaround
Disable all block-based cipher suites in your server’s SSL/TLS configuration. Only use this workaround if you can't enable TLS 1.2 or TLS 1.3 on servers and in browsers.