Indian Scout 2025: CAN bus-off attack silently bypasses anti-theft shutdown

Expected behavior violation in the in-vehicle network of the Indian Motorcycle Scout Bobber + Tech 2025 model year allows an adjacent-network attacker to bypass the motorcycle's anti-theft shutdown by forcing the Wireless Control Module (WCM) into the CAN bus-off state. Using a well-known CAN error-frame injection technique against a periodic WCM transmission, the attacker drives the WCM CAN controller's transmit error counter past the bus-off threshold, after which the WCM stops transmitting all messages, including the shutdown command. Peer ECUs do not interpret WCM silence as a security event and continue normal operation, allowing the motorcycle to be operated despite the immobilizer never having been unlocked.

Specific protocol details have been withheld pending vendor remediation.

Recommended remediation:

Treat absence of the WCM heartbeat as a security event in peer ECUs — command shutdown if the WCM's periodic message is missing beyond a bounded interval. Authenticate the heartbeat with AUTOSAR SecOC or equivalent to prevent post-silence spoofing. Auto-recover the WCM from bus-off and log the event.

Scott Sheahan, Rustic Security LLC (finder)

2025-03-26: Reported to Indian Motorcycle (Polaris Inc.) by Rustic Security LLC under responsible disclosure

2026-05-29: Public disclosure by ASRG