title: Multiple Cisco UCS-Based Products UEFI Secure Boot Bypass Vulnerability
description: A vulnerability in the firmware of the Cisco UCS C-Series Rack Servers could allow an authenticated, physical attacker to bypass Unified Extensible Firmware Interface (UEFI) Secure Boot validation checks and load a compromised software image on an affected device. The vulnerability is due to improper validation of the server firmware upgrade images. An attacker could exploit this vulnerability by installing a server firmware version that would allow the attacker to disable UEFI Secure Boot. A successful exploit could allow the attacker to bypass the signature validation checks that are done by UEFI Secure Boot technology and load a compromised software image on the affected device. A compromised software image is any software image that has not been digitally signed by Cisco.
problem types: CWE-347
affected:
{
product: Cisco Identity Services Engine Software
vendor: Cisco
versions:
status: affected, version: n/a
}
metrics:
cvssV3_0: [
attackComplexity: LOW
attackVector: PHYSICAL
availabilityImpact: HIGH
baseScore: 6.2
baseSeverity: MEDIUM
confidentialityImpact: HIGH
integrityImpact: HIGH
privilegesRequired: HIGH
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.0/AV:P/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
version: 3.0
]
exploits: The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.