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Vulnerabilities

Vulnerability · CVE-2021-31728

MalwareFox AntiMalware zam64.sys and zam32.sys Incorrect Acces Control Vulnerability

Published Jun 5, 2025 · catalog updated Jun 5, 2025 · MalwareFox AntiMalware zam64.sys and

Patch now

CVE-2021-31728 is in the CISA known-exploited catalog. Confirm MalwareFox AntiMalware zam64.sys and against the vendor advisory and apply that fix. The CVSS score does not change the priority.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (MalwareFox AntiMalware zam64.sys and).
  • No version range is stored. A customer cannot check an installed version against this record.
Severity
Unknown—
Known exploitation
CISA KEV and VulnCheck KEV
EPSS
3.40%
Remediation
Remediation guidance
Affected products
vendor malwarefox antimalware

Incorrect access control in zam64.sys, zam32.sys in MalwareFox AntiMalware 2.74.0.150 allows a non-privileged process to open a handle to \.\ZemanaAntiMalware, register itself with the driver by sending IOCTL 0x80002010, allocate executable memory using a flaw in IOCTL 0x80002040, install a hook with IOCTL 0x80002044 and execute the executable memory using this hook with IOCTL 0x80002014 or 0x80002018, this exposes ring 0 code execution in the context of the driver allowing the non-privileged process to elevate privileges.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • vendor malwarefox antimalwareversion unspecified

How to fix CVE-2021-31728

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

CVE-2021-31728 is in the CISA known-exploited catalog. Confirm MalwareFox AntiMalware zam64.sys and against the vendor advisory and apply that fix. The CVSS score does not change the priority.

Which versions are affected?

Affected version ranges are not on this record. Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.

What should an analyst verify?

No weakness class is stored. EPSS 3.40%. The CISA KEV listing is the exploitation evidence. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Jun 5, 2025 · VulnCheck KEV

    Detected

    Incorrect access control in zam64.sys, zam32.sys in MalwareFox AntiMalware 2.74.0.150 allows a non-privileged process to open a handle to \.\ZemanaAntiMalware, register itself with the driver by sending IOCTL 0x80002010, allocate executable memory using a flaw in IOCTL 0x80002040, install a hook with IOCTL 0x80002044 and execute the executable memory using this hook with IOCTL 0x80002014 or 0x8000

  2. Jun 5, 2025 · CISA KEV

    Known exploited

    Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.

Sources

  • CVE.orgVulnerability recordCVE-2021-31728

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2021-31728

    30-day exploitation probability 3.4%

    first.org
  • VulnCheck KEVConfirmed exploitationCVE-2021-31728

    Incorrect access control in zam64.sys, zam32.sys in MalwareFox AntiMalware 2.74.0.150 allows a non-privileged process to open a handle to \.\ZemanaAntiMalware, register itself with the driver by sending IOCTL 0x80002010, allocate executable memory using a flaw in IOCTL 0x80002040

    vulncheck.com

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.