CVE-2021-0943
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedIn MMU_MapPages of TBD, there is a possible out of bounds write due to improper input validation. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android SoCAndroid ID: A-238916921
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceIn the MMU_MapPages function of Android SoC, improper input validation allows an out-of-bounds write, enabling local privilege escalation without user interaction.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE dataall versionsCVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Local
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
-
Check Android security patch levelGo to Settings > About Phone > Security Patch Level or run 'getprop ro.build.version.security_patch' via ADB shell. Compare the date to when the CVE was fixed (CVE-2021-0943 was fixed in the January 2022 Android Security Bulletin).Affected if The security patch level is earlier than January 2022 or the field is empty/unavailable.
-
Identify kernel versionRun 'uname -r' via ADB shell or check /proc/version. This reveals the kernel build version.Affected if The kernel version predates the patched builds released by your SoC/vendor after January 2022.
-
Determine SoC vendor and modelRun 'getprop ro.board.platform' or 'getprop ro.hardware' via ADB shell to identify the System-on-Chip and hardware platform.Affected if The device uses a SoC that has not received vendor-specific patches for the MMU_MapPages input validation flaw.
-
Check for kernel source availabilityIf using a custom kernel or ROM, inspect the MMU_MapPages function in the kernel source code for bounds checking on the input parameters (page count, virtual address range).Affected if The source code lacks proper input validation bounds checking before the memory mapping operation.
A device is affected if it has not received the vendor-specific kernel patch addressing MMU_MapPages input validation, typically indicated by a security patch level before January 2022 or an unpatched kernel version.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataApply security updates from Android/SoC vendors that address input validation in the MMU_MapPages function; this is a kernel-level memory management fix requiring vendor-specific patches.
- Consultation6.0 h
- Implementation12.0 h
- Testing8.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $8,448.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-0943 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2021-0943 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data