CVE-2025-35968 in Slim Bootloader
Summary
by MITRE • 11/11/2025
Protection mechanism failure in the UEFI firmware for the Slim Bootloader within firmware may allow an escalation of privilege. Startup code and smm adversary with a privileged user combined with a high complexity attack may enable escalation of privilege. This result may potentially occur via local access when attack requirements are present without special internal knowledge and requires no user interaction. The potential vulnerability may impact the confidentiality (high), integrity (high) and availability (high) of the vulnerable system, resulting in subsequent system confidentiality (none), integrity (none) and availability (none) impacts.
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Analysis
by VulDB Data Team • 11/11/2025
The vulnerability identified as CVE-2025-35968 represents a critical protection mechanism failure within the UEFI firmware implementation of the Slim Bootloader firmware ecosystem. This flaw exists at the foundational level of system security where the firmware's integrity protection mechanisms fail to properly enforce privilege boundaries during system startup and system management mode operations. The vulnerability manifests as a failure in the firmware's ability to maintain proper access controls and privilege separation, creating an exploitable condition that could allow unauthorized elevation of privileges from a lower-privileged state to a higher-privileged state.
The technical nature of this vulnerability stems from weaknesses in the firmware's startup code execution and system management mode handling within the Slim Bootloader framework. According to CWE classification, this represents a weakness in the protection mechanism where the system fails to properly validate or enforce privilege levels during critical firmware initialization phases. The attack vector requires local access with a privileged user account and can be executed with high complexity, indicating that while the attack itself is not trivial, it does not require extensive specialized knowledge or access to specific system components. The combination of startup code and SMM (System Management Mode) adversary conditions creates a particularly dangerous scenario where an attacker could leverage the firmware's privilege escalation mechanisms to gain elevated system privileges.
The operational impact of this vulnerability extends across all three fundamental security properties of the system. The high impact ratings for confidentiality, integrity, and availability indicate that successful exploitation could result in complete system compromise with no residual protection mechanisms remaining. When a system is vulnerable to this type of privilege escalation, it essentially removes the firmware-level security controls that normally protect against malicious modifications, unauthorized access, and system disruption. The potential for complete system compromise means that an attacker could gain root-level access to the firmware, potentially enabling persistent backdoor installation, complete system state manipulation, and undetectable malware persistence.
The implications of this vulnerability align with ATT&CK framework techniques related to privilege escalation and firmware manipulation. Specifically, this vulnerability maps to techniques involving firmware modification and boot process exploitation, where attackers can leverage the firmware's trust model to gain unauthorized system control. The requirement for local access and privileged user context suggests that this vulnerability could be exploited by insider threats or attackers who have already gained initial system access through other means. The lack of user interaction requirements and the potential for automatic exploitation make this particularly dangerous in environments where system administrators or authorized users may be targeted. Organizations should implement comprehensive firmware security monitoring, regular firmware updates, and strict access controls to mitigate the risk of exploitation, while also considering hardware-based security features such as measured boot and firmware integrity verification mechanisms to provide additional protection layers against such attacks.