Local privilege escalation via user-buffer bounds error
Published Mar 16, 2022 · Updated Oct 21, 2025
Out-of-bounds write in the Arm Mali GPU kernel driver on Android allows local users to gain elevated privileges without user interaction. kbase_jd_user_buf_pin_pages in mali_kbase_mem.c mishandles user-buffer page pinning logic and writes beyond the intended memory bounds. Exploitation requires local low-privileged code on a device with the affected driver and can yield kernel-level control; Google reported limited, targeted exploitation.
Summary
What happened
Out-of-bounds write in the Arm Mali GPU kernel driver on Android allows local users to gain elevated privileges without user interaction. kbase_jd_user_buf_pin_pages in mali_kbase_mem.c mishandles user-buffer page pinning logic and writes beyond the intended memory bounds. Exploitation requires local low-privileged code on a device with the affected driver and can yield kernel-level control; Google reported limited, targeted exploitation.
The record
- CVE
- CVE-2021-39793
- Published
- Mar 16, 2022
- Updated
- Oct 21, 2025
- Vendor
- Arm
- Product
- Mali
- Classifications
- CWE-787, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Mar 7, 2022Exploitation reportedLimited targeted exploitation reported by Google
- Mar 16, 2022CVE publishedPublication date reported by the CVE source.
- Apr 15, 2022Exploitation reportedCISA Known Exploited Vulnerabilities listing
- 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=Android kernel
What conditions does exploitation require?
What is affected?
Published CVSS scores
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.
Public exploit references
- Two bugs with one PoC Rooting Pixel 6 from Android 12 to Android 13proof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Reported exploitation
- Limited targeted exploitation reported by Googlereported exploitation
- CISA Known Exploited Vulnerabilities listingknown exploited catalog
Technologies
Your stack
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Your stack
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