Cisco NX-OS PTP feature (Nexus 5500/5600/6000): An unauthenticated remote attacker takes down a Nexus switch through

Impact

An unauthenticated remote attacker takes down a Nexus switch through the PTP subsystem. PTP is one of the few unauthenticated protocols that switches process in the control plane by design, so it is a reliable path to the CPU on every device that has it enabled. The Cisco IOS equivalent is CVE-2018-0473.

Who can reach it

Unauthenticated, remote — PTP packets reaching the switch's PTP-enabled interfaces.

What to do

NX-OS upgrade plus reload. Immediate config mitigation: disable PTP on interfaces that face tenant workloads and keep it only on the links that actually need it — live change, no reload.

References

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