February 25, 2019
Categorized: Low Severity
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The Baseboard Management Controller (BMC) is a third-party component designed to enable remote management of a server for initial provisioning, operating system reinstall and troubleshooting. As part of IBM Cloud’s Bare Metal Server offering, clients have access to the BMC.
On some system models offered by IBM Cloud and other cloud providers, a malicious attacker with access to the provisioned system could overwrite the firmware of the BMC. The system could then be returned to the hardware pool, where the compromised BMC firmware could then be used to attack the next user of the system.
The BMC has limited processing power and memory, which makes these types of attacks difficult. IBM has found no indication that this vulnerability has been exploited for malicious purposes. In addition, all clients of IBM Cloud receive a private network for their BMCs, separate from the private networks containing other clients’ BMCs and unprovisioned BMCs.
IBM has responded to this vulnerability by forcing all BMCs, including those that are already reporting up-to-date firmware, to be reflashed with factory firmware before they are re-provisioned to other customers. All system event logs in BMC are erased and all passwords to the BMC/ipmi device are regenerated.
Workarounds and Mitigations:
IBM Secure Engineering Web Portal
25 February 2019: Original version published