CyberSecBulletin
CVE-2022-4020NVD status: Modified

Aspire A315-22: Incorrect Default Permissions

Published Updated By the CyberSecBulletin desk

CVE-2022-4020 is a high-severity incorrect default permissions vulnerability in Aspire A315-22 from Acer, with a CVSS 3.1 base score of 8.2 out of 10. It can be exploited with local access to the system by an attacker with administrator privileges, without any action from a user. The record lists version 1.11 as the first without the flaw, so updating Aspire A315-22 to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.25% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Aspire A315-22 to 1.11 or a later version.
  2. Update Aspire A115-21 to 1.11 or a later version.
  3. Update Aspire A315-22G to 1.11 or a later version.
  4. Read the advisory on community.acer.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
AcerAspire A315-221.04 up to, but not including, 1.111.11
AcerAspire A115-211.04 up to, but not including, 1.111.11
AcerAspire A315-22G1.04 up to, but not including, 1.111.11
AcerExtensa EX215-211.04 up to, but not including, 1.111.11
AcerExtensa EX215-21G1.04 up to, but not including, 1.111.11
AcerAspire A315-22g FirmwareNot specified in the recordNot stated
AcerAspire A115-21 FirmwareNot specified in the recordNot stated
AcerAspire A315-22 FirmwareNot specified in the recordNot stated
AcerExtensa Ex215-21 FirmwareNot specified in the recordNot stated
AcerExtensa Ex215-21g FirmwareNot specified in the recordNot stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
HighAdministrator-level access is required first.
User interaction
NoneNo action by a victim is required.
Scope
ChangedThe attack can reach beyond the vulnerable component into other systems.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.18.1HighCNA (eset.com)
CVSS 3.18.2HighNVD

Official description

Vulnerability in the HQSwSmiDxe DXE driver on some consumer Acer Notebook devices may allow an attacker with elevated privileges to modify UEFI Secure Boot settings by modifying an NVRAM variable.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Incorrect Default Permissions

During installation, installed file permissions are set to allow anyone to modify those files.

How developers prevent this class of flaw

  • The architecture needs to access and modification attributes for files to only those users who actually require those actions.
  • Compartmentalize the system to have safe areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.

More Incorrect Default Permissions vulnerabilities (CWE-276)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Incorrect Default Permissions vulnerabilities

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