CVE-2021-0147 in Power Management Controller
Summary
by MITRE • 02/10/2022
Improper locking in the Power Management Controller (PMC) for some Intel Chipset firmware before versions pmc_fw_lbg_c1-21ww02a and pmc_fw_lbg_b0-21ww02a may allow a privileged user to potentially enable denial of service via local access.
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Analysis
by VulDB Data Team • 02/14/2022
The vulnerability identified as CVE-2021-0147 represents a critical flaw in the Power Management Controller (PMC) firmware implementation within certain Intel chipsets. This issue affects firmware versions prior to pmc_fw_lbg_c1-21ww02a and pmc_fw_lbg_b0-21ww02a, indicating a specific window of affected products that require immediate attention. The vulnerability stems from improper locking mechanisms within the PMC subsystem, which governs power management operations for the system's hardware components. The PMC serves as a crucial interface between the operating system and hardware power states, making it a prime target for malicious actors seeking to disrupt system operations or escalate privileges.
The technical flaw manifests in the inadequate synchronization mechanisms that protect critical PMC resources during concurrent access scenarios. When multiple processes or threads attempt to modify power management states simultaneously, the absence of proper locking protocols creates race conditions that can result in unpredictable behavior. This improper locking design allows a privileged user account to exploit the vulnerability through local access, potentially manipulating power management registers in ways that were not intended by the firmware architects. The vulnerability operates at the firmware level, making it particularly dangerous as it can bypass traditional operating system security controls and access hardware-level resources directly.
From an operational impact perspective, this vulnerability creates significant risk for system availability and stability. A malicious user with local access and appropriate privileges could potentially trigger denial of service conditions that disrupt normal system operations, forcing the system into unstable power states or preventing proper power management functionality. The implications extend beyond simple service disruption as improper power management can lead to system crashes, data corruption, or even hardware damage in extreme scenarios. The local access requirement limits the attack surface compared to remote exploits, but it still represents a serious threat in environments where privileged accounts are compromised or where insider threats exist.
Mitigation strategies should focus on immediate firmware updates to the latest versions that contain the corrected locking mechanisms. System administrators must prioritize updating affected Intel chipsets to versions pmc_fw_lbg_c1-21ww02a or pmc_fw_lbg_b0-21ww02a, as these releases incorporate the necessary synchronization improvements. Additionally, organizations should implement strict access controls and privilege management to minimize the number of users with local access to systems running affected firmware. Network segmentation and monitoring solutions should be deployed to detect anomalous power management behavior that might indicate exploitation attempts. The vulnerability aligns with CWE-362, which addresses race conditions in concurrent programming, and represents a potential ATT&CK technique under T1499.002 for endpoint denial of service. Organizations should also consider implementing firmware integrity checking mechanisms to detect unauthorized modifications to power management controllers.