CVE-2021-28664Known exploitationPublic exploit

Privilege escalation via unchecked page-import permissions

Published May 10, 2021 · Updated Oct 21, 2025

Improper memory access in Arm Mali GPU Kernel Driver allows local users to gain kernel privileges or crash the device through crafted page imports. The kbase_mem_from_user_buffer function calls get_user_pages without a write check when only CPU-write permission is requested, then records the imported region as writable. Access to the Mali device from an unprivileged process is sufficient to rewrite read-only mappings, enabling memory corruption, privilege escalation, or a device crash.

CVSS severity8.8
High
EPSS probability5.41%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper memory access in Arm Mali GPU Kernel Driver allows local users to gain kernel privileges or crash the device through crafted page imports. The kbase_mem_from_user_buffer function calls get_user_pages without a write check when only CPU-write permission is requested, then records the imported region as writable. Access to the Mali device from an unprivileged process is sufficient to rewrite read-only mappings, enabling memory corruption, privilege escalation, or a device crash.

The record

CVE
CVE-2021-28664
Published
May 10, 2021
Updated
Oct 21, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 10, 2021CVE publishedPublication date reported by the CVE source.
  2. Oct 21, 2025Record 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

8.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
9.0NIST NVDAV:N/AC:L/Au:S/C:C/I:C/A:C

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationReported
Public exploitPublished

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1068Exploitation for Privilege Escalation

Public exploit references

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

Reported exploitation

Technologies

Your stack

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Your stack

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