CVE-2021-28663

Exp

The Arm Mali GPU kernel driver allows privilege escalation or information disclosure because GPU memory operations are mishandled, leading to a use-after-free. This affects Bifrost r0p0 through r28p0 before r29p0, Valhall r19p0 through r28p0 before r29p0, and Midgard r4p0 through r30p0.

Published: 2021-05-10 Last update: 2025-11-03 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2021-28663 is rated Critical Active Threat (91.9/100): CVSS High severity, with medium exploitation likelihood (EPSS 3.62%). Core evidence: CISA KEV confirms active exploitation (added 2021-11-03) affecting Arm / Mali Graphics Processing Unit (GPU). a weakness (CWE-416) Unauthenticated remote administrative access may be possible. Mandatory action: The CISA remediation deadline has passed—treat as an emergency patch priority.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

CISA KEV Record for CVE-2021-28663

Name: Arm Mali Graphics Processing Unit (GPU) Use-After-Free Vulnerability · CISA KEV detail

Exploit added: 2021-11-03

Action due: 2021-11-17

Required action: Apply updates per vendor instructions.

Public exploit references (Exploit-DB) for CVE-2021-28663

EDB-ID Source Kind Published Link
nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2021-28663

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-12 2.66% 3.62% +0.96%
2 2026-03-17 2.29% 2.66% +0.37%
3 2026-03-14 2.29%

Full EPSS history (25 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-28663

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.8 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
2.8 5.9 [email protected]
8.8 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
2.8 5.9 134c704f-9b21-4f2e-91b3-4a467353bcc0
9.0 2.0 HIGH
AV:N/AC:L/Au:S/C:C/I:C/A:C Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:S)
A single authentication is required.
Confidentiality impact (C:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
8.0 10.0 [email protected]

Weakness enumeration for CVE-2021-28663

Affected software / configurations for CVE-2021-28663

Vendor Product Version Raw CPE
arm bifrost_gpu_kernel_driver >= r0p0, < r29p0 cpe:2.3:a:arm:bifrost_gpu_kernel_driver:*:*:*:*:*:*:*:*
arm midgard_gpu_kernel_driver >= r4p0, < r31p0 cpe:2.3:a:arm:midgard_gpu_kernel_driver:*:*:*:*:*:*:*:*
arm valhall_gpu_kernel_driver >= r19p0, < r29p0 cpe:2.3:a:arm:valhall_gpu_kernel_driver:*:*:*:*:*:*:*:*

References for CVE-2021-28663

cvelogic Threat Intelligence