A flaw in some Acer laptops can be used to bypass security features

ESET announced the discovery of a vulnerability impacting Acer laptops that can allow an attacker to deactivate UEFI Secure Boot.

ESET researchers announced in a series of tweets the discovery of a vulnerability impacting Acer laptops, the issue can allow an attacker to deactivate UEFI Secure Boot.

The experts explained that the flaw, tracked as CVE-2022-4020, is similar to the Lenovo vulnerabilities the company disclosed earlier this month.

Same as in Lenovo’s case, an attacker can trigger the issue to deactivate the UEFI Secure Boot by creating NVRAM variable directly from OS.

The Secure Boot is a security feature of the latest Unified Extensible Firmware Interface (UEFI) 2.3.1 designed to detect tampering with boot loaders, key operating system files, and unauthorized option ROMs by validating their digital signatures. “Detections are blocked from running before they can attack or infect the system specification.”

An attacker that is able to bypass the Secure Boot could bypass any security measure running on the machine and achieve persistence even in case the OS is reinstalled.

The CVE-2022-4020 impacts certain versions of Acer Aspire A315-22 from Acer, the vulnerability resides in the HQSwSmiDxe DXE driver on these consumer Acer Notebook devices. Similar to the Lenovo issues an attacker with elevated privileges can exploit the bug to modify UEFI Secure Boot settings by modifying an NVRAM variable. The DXE driver BootOrderDxe simply disables UEFI Secure Boot if NVRAM variables “BootOrderSecureBootDisable” exists.

ESET explained that the flaws affects only 5 devices Aspire A315-22/22G, A115-21 and Extensa EX215-21/21G. According to Acer, an update should be distributed as a critical Windows update. Alternatively, the updated BIOS version can be downloaded here.

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Pierluigi Paganini

(SecurityAffairs – hacking, Moshen Dragon)

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Pierluigi Paganini

Pierluigi Paganini is member of the ENISA (European Union Agency for Network and Information Security) Threat Landscape Stakeholder Group and Cyber G7 Group, he is also a Security Evangelist, Security Analyst and Freelance Writer. Editor-in-Chief at "Cyber Defense Magazine", Pierluigi is a cyber security expert with over 20 years experience in the field, he is Certified Ethical Hacker at EC Council in London. The passion for writing and a strong belief that security is founded on sharing and awareness led Pierluigi to find the security blog "Security Affairs" recently named a Top National Security Resource for US. Pierluigi is a member of the "The Hacker News" team and he is a writer for some major publications in the field such as Cyber War Zone, ICTTF, Infosec Island, Infosec Institute, The Hacker News Magazine and for many other Security magazines. Author of the Books "The Deep Dark Web" and “Digital Virtual Currency and Bitcoin”.