HSA-25-0003: Improper certificate validation in the remote service interface of the SC-340M

The SC-340M connects to its equipment maker's service network through the remote service interface, an Ethernet connection protected by TLS with certificates on both sides. In platform firmware 4.11 and earlier, the controller checked that the server's certificate was issued by an authority in its trust list, but did not check that the certificate was issued for the equipment maker's service network.

An attacker who could intercept the controller's traffic on the hospital's or the service provider's network, and who held any certificate from an authority in the trust list, could present it to the controller and impersonate the service network. The attacker could then read logs and, where the equipment maker has enabled it, install firmware signed by the equipment maker. Firmware not signed by the equipment maker is always refused.

Platform firmware 4.12, released to OEM customers on September 30, 2025, checks the server certificate against the identity configured by the equipment maker.

Because the SC-340M is built into our customers' equipment, Hosaka does not supply firmware to end users. Owners of equipment containing the SC-340M should contact the manufacturer of the equipment for updates. Hosaka has notified all OEM customers.

Until the update is installed, the remote service interface should be connected only to a network segment reserved for the equipment maker's service traffic.