One way to defeat a multi-level security solution is to leak data via

A 'bypass regulator' is not a recognized term in information security and does not describe any known technique for defeating multi-level security solutions.

Steganography conceals the existence of data within carrier media but does not by itself create a pathway that circumvents the mandatory access controls enforced by an MLS system.

A covert channel is a communication path not designed for information transfer that allows a process to move data in a way that violates a system's security policy. In multi-level security environments, covert channels - whether storage-based or timing-based - can transfer data across security domain boundaries without being detected or blocked by mandatory access controls, effectively defeating the MLS model.

Asymmetric routing is a network condition where traffic takes different paths in each direction - it is a routing anomaly unrelated to bypassing multi-level security access controls.