Cisco Unified Computing System Managed
Monthly
UEFI Secure Boot bypass in Cisco UCS Servers and UCS-based appliances allows authenticated users with 'user' or 'admin' role credentials - or unauthenticated attackers with physical device access - to disable Secure Boot protections and execute unauthorized software at boot time. The flaw stems from UEFI Shell memory-write commands remaining accessible while Secure Boot is active, enabling direct manipulation of Secure Boot validation variables in UEFI memory. A successful exploit undermines firmware integrity controls, potentially allowing persistent pre-OS implants or untrusted bootloaders on enterprise server infrastructure. No public exploit code or CISA KEV entry has been identified at time of analysis.
UEFI Secure Boot bypass in Cisco UCS Servers and UCS-based appliances allows authenticated users with 'user' or 'admin' role credentials - or unauthenticated attackers with physical device access - to disable Secure Boot protections and execute unauthorized software at boot time. The flaw stems from UEFI Shell memory-write commands remaining accessible while Secure Boot is active, enabling direct manipulation of Secure Boot validation variables in UEFI memory. A successful exploit undermines firmware integrity controls, potentially allowing persistent pre-OS implants or untrusted bootloaders on enterprise server infrastructure. No public exploit code or CISA KEV entry has been identified at time of analysis.