Security readout for executives and security teams
Plain-English summary
CVE-2021-31728 is a local privilege escalation issue in MalwareFox AntiMalware 2.74.0.150 drivers. A normal local process could abuse weak driver access controls to run code with kernel privileges. This is serious on endpoints where the affected driver is installed, but the provided sources do not show remote exploitation or active exploitation.
Executive priority
Prioritize remediation on endpoints where MalwareFox AntiMalware 2.74.0.150 is installed, especially shared workstations or systems exposed to untrusted local code. Business urgency is high when the affected driver is present.
Technical view
The issue affects zam64.sys and zam32.sys associated with MalwareFox AntiMalware 2.74.0.150. The driver interface allowed non-privileged processes to interact with privileged driver functionality, leading to ring 0 code execution and privilege escalation. Public source detail exists, but CVSS, CWE, and broader version impact are not provided in the bundle.
Likely exposure
Exposure appears limited to Windows systems running MalwareFox AntiMalware 2.74.0.150 with the affected zam64.sys or zam32.sys driver loaded. The bundle does not prove other versions or products are affected.
Exploitation context
The CVE describes local exploitation requiring a non-privileged process on the target host. The source bundle says KEV is false and provides no cited evidence of active exploitation in the wild.
Researcher notes
The public description gives enough detail to classify this as kernel-level local privilege escalation. Evidence is incomplete for CVSS, CWE mapping, vendor patch status, exploit prevalence, and affected versions beyond MalwareFox AntiMalware 2.74.0.150.
Mitigation direction
- Inventory endpoints for MalwareFox AntiMalware 2.74.0.150 and affected drivers.
- Check MalwareFox or Zemana guidance for fixed versions or removal instructions.
- If no longer required, uninstall the affected software and reboot to unload drivers.
- If a fixed release is identified by the vendor, update promptly.
- Monitor endpoints for suspicious local privilege escalation behavior.
Validation and detection
- Confirm whether zam64.sys or zam32.sys is present and loaded on endpoints.
- Verify installed MalwareFox AntiMalware version against 2.74.0.150.
- Review EDR telemetry for unusual unprivileged processes interacting with antivirus drivers.
- Confirm remediation by verifying the vulnerable driver is updated, removed, or no longer loaded.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
Execution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-31728 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/irql0/CVE-2021-31728/blob/master/CVE-2021-31728.mdCVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.