CVE-2021-31727Public exploit

Local privilege escalation via unrestricted driver IOCTLs

Published May 17, 2021 · Updated Aug 3, 2024

Incorrect access control in MalwareFox AntiMalware 2.74.0.150 allows local users to execute arbitrary ring 0 code through driver IOCTLs. The zam64.sys and zam32.sys drivers let an unprivileged process register itself through IOCTL 0x80002010, then perform unrestricted disk reads or writes through IOCTLs 0x80002014 and 0x80002018. Local access is required; overwriting the boot sector or critical pagefile code provides a path to kernel code execution, system corruption, or service interruption.

CVSS severity7.8
High
EPSS probability0.37%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect access control in MalwareFox AntiMalware 2.74.0.150 allows local users to execute arbitrary ring 0 code through driver IOCTLs. The zam64.sys and zam32.sys drivers let an unprivileged process register itself through IOCTL 0x80002010, then perform unrestricted disk reads or writes through IOCTLs 0x80002014 and 0x80002018. Local access is required; overwriting the boot sector or critical pagefile code provides a path to kernel code execution, system corruption, or service interruption.

The record

CVE
CVE-2021-31727
Published
May 17, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-863, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 17, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.2NIST NVDAV:L/AC:L/Au:N/C:C/I:C/A:C
7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-863Incorrect Authorization
T1068Exploitation for Privilege Escalation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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