Recent discoveries have unveiled critical vulnerabilities within the BIOS firmware of Lenovo’s IdeaCentre and Yoga All-In-One (AIO) desktop systems. These flaws, if exploited, could allow attackers with elevated privileges to execute arbitrary code, potentially compromising the entire system.
Understanding the Vulnerabilities
The identified vulnerabilities reside in the System Management Mode (SMM) of the BIOS firmware. SMM is a highly privileged execution mode in x86 processors, designed for handling system-wide functions like power management and hardware control. Due to its elevated privileges, any vulnerabilities within SMM can have severe implications.
Six distinct Common Vulnerabilities and Exposures (CVE) identifiers have been assigned to these issues, each carrying a CVSS score of 8.2, indicating high severity:
1. CVE-2025-4421: A memory corruption issue in SMM’s CPU protocol service, allowing attackers to write data beyond allocated memory boundaries, potentially overwriting critical system code.
2. CVE-2025-4422: An out-of-bounds write vulnerability in SMM’s platform configuration database protocol, enabling attackers to corrupt memory and execute malicious code.
3. CVE-2025-4423: A buffer overflow in the setup automation module, permitting attackers to inject and execute arbitrary code within the highly privileged SMM environment.
4. CVE-2025-4424: An input validation flaw that allows attackers to make unauthorized calls to system variable functions with malicious parameters, potentially altering system configurations.
5. CVE-2025-4425: A stack-based buffer overflow in system interrupt handlers, which can be exploited to overwrite return addresses and execute attacker-controlled code.
6. CVE-2025-4426: An information disclosure vulnerability that leaks sensitive data from protected system management memory (SMRAM) to unauthorized processes.
Exploiting these vulnerabilities requires local administrative access. However, once exploited, they can lead to complete system compromise, allowing attackers to install persistent malware that survives OS reinstalls and bypasses security features like Secure Boot.
Affected Lenovo Products
The vulnerabilities impact several Lenovo product lines, including:
– IdeaCentre AIO 3: Models 24ARR9 and 27ARR9.
– Yoga AIO: Models 27IAH10, 32ILL10, and 9 32IRH8.
These issues specifically affect the EfiSmiServices components, including gEfiSmmCpuProtocol and EfiPcdProtocol implementations within the SMM modules.
Discovery and Disclosure
The vulnerabilities were discovered by the BINARLY Research team, who conducted a coordinated disclosure process. Their findings highlight the critical nature of these SMM-level security flaws and the potential risks they pose to affected systems.
Lenovo’s Response and Mitigation
In response to these findings, Lenovo has released BIOS updates to address the vulnerabilities:
– IdeaCentre Models: BIOS version L05.05.40.011803.172079 has been released, with the minimum fixed version being O6BKT1AA, now available for download.
– Yoga AIO Models: Remediation timelines extend through late 2025, with fixes scheduled for:
– September 30, 2025: Yoga AIO 32ILL10 and 9 32IRH8.
– November 30, 2025: Yoga AIO 27IAH10.
Users are strongly advised to update their systems through Lenovo’s support portal and enable automatic update mechanisms where available to mitigate potential risks.
Implications of the Vulnerabilities
The exploitation of these vulnerabilities could have severe consequences:
– Persistent Malware: Attackers could install firmware-level malware that persists across system reboots and OS reinstalls, making detection and removal challenging.
– Bypassing Security Features: By compromising SMM, attackers can disable security features like Secure Boot, Kernel DMA Protection, and hypervisor memory isolation, leaving systems vulnerable to further attacks.
– System Integrity Compromise: With the ability to execute code at the SMM level, attackers can gain control over critical system functions, leading to potential data breaches and system instability.
Recommendations for Users
To protect against these vulnerabilities, users should:
1. Update BIOS Firmware: Regularly check for and apply BIOS updates provided by Lenovo to ensure vulnerabilities are patched.
2. Monitor System Activity: Be vigilant for unusual system behavior that could indicate compromise, such as unexpected reboots or performance degradation.
3. Limit Administrative Access: Restrict administrative privileges to trusted users to reduce the risk of local exploitation.
4. Implement Security Best Practices: Utilize comprehensive security solutions, keep software up to date, and educate users on recognizing potential threats.
Conclusion
The discovery of these critical BIOS vulnerabilities in Lenovo’s IdeaCentre and Yoga AIO systems underscores the importance of firmware security in modern computing. Users must take proactive steps to update their systems and adhere to security best practices to mitigate potential risks. Staying informed about such vulnerabilities and responding promptly is crucial in maintaining system integrity and protecting sensitive information.
