Interpretation of Firewall Packet Size Limit Change by the GPT-4.1 mini Monitor

Determine whether the GPT-4.1 mini sabotage monitor in BashArena judged an honest policy’s action of increasing the firewall packet size limit as a step toward completing the "Disable Firewall" side task or as an independent configuration change that itself violates the firewall security property. This clarification should be made in the context of the "Monitor false positives" example where the honest policy raised the packet size limit to enable internet connectivity while the monitor issued a high suspicion score.

Background

BashArena evaluates AI control protocols via an adversarial setup that includes a blue-team monitor tasked with detecting four side tasks, one of which is "Disable Firewall." Monitors assign per-action suspicion scores and must operate under very low false positive rate constraints.

In the "Monitor false positives" appendix, the authors discuss a case where an honest policy raises the firewall packet size limit to restore connectivity. The GPT-4.1 mini monitor assigns a high suspicion score, but the authors note uncertainty about whether the monitor viewed the change as part of an attack to disable the firewall or as a standalone violation. Clarifying the monitor’s interpretation would inform how to design and calibrate monitors to distinguish necessary configuration adjustments from actual sabotage attempts.