Downgrade Attack

Downgrade attack↗ is an attack that forces a connection or system to fall back to an older, weaker version of a protocol or encryption↗ standard, one with known vulnerabilities, instead of using the strongest option both sides actually support.

For example, an attacker might trick a browser and server into using an outdated, breakable version of TLS instead of a modern one. Disabling support for legacy protocols entirely, rather than just preferring modern ones, is the most reliable defense.