#VU77971 Use-after-free in ARM products - CVE-2021-29256

Vulnerability identifier: #VU77971

Vulnerability risk: High

CVSSv4.0: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:A/U:Amber]

CVE-ID: CVE-2021-29256

CWE-ID: CWE-416

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
Midgard GPU Kernel Driver
Hardware solutions / Drivers
Bifrost GPU Kernel Driver
Hardware solutions / Drivers
Valhall GPU Kernel Driver
Hardware solutions / Drivers

Vendor: ARM

Description

The vulnerability allows a local application to escalate privileges on the system.

The vulnerability exists due to improper operations on GPU memory. A local application can trigger a use-after-free error and execute arbitrary code with elevated privileges.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Midgard GPU Kernel Driver: before r31p0

Bifrost GPU Kernel Driver: before r30p0

Valhall GPU Kernel Driver: before r30p0

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External links
https://developer.arm.com/Arm%20Security%20Center/Mali%20GPU%20Driver%20Vulnerabilities#CVE-2021-29256
https://source.android.com/docs/security/bulletin/2023-07-01

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Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

Yes. This vulnerability is being exploited in the wild.