CVE-2021-25339
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 · uneditedImproper address validation in HArx in Samsung mobile devices prior to SMR Mar-2021 Release 1 allows an attacker, given a compromised kernel, to corrupt EL2 memory.
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 confidenceImproper address validation in the HArx component of Samsung mobile devices allows an attacker with an already compromised kernel to corrupt EL2 (Exception Level 2) memory, potentially escalating privileges or bypassing security boundaries.
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 data= 10.0= 11.0CVSS 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
- Physical
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- High
- Availability
- Low
CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L
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.
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Confirm device is a Samsung mobile deviceCheck system settings under About phone > Device name or manufacturer. Samsung devices will show Samsung as the manufacturer.Affected if Device is not a Samsung mobile device (this vulnerability only affects Samsung mobile devices)
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Verify Android version is 10.0 or 11.0Navigate to Settings > About phone > Android version. Confirm the exact version number displayed.Affected if Android version is 10.0 or 11.0 exactly (these are the affected versions listed)
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Check Samsung Android security patch levelGo to Settings > About phone > Software information > Build number. The SMR (Samsung Maintenance Release) date is encoded in the build number - compare against the Mar-2021 Release 1 patch date.Affected if Security patch level is earlier than March 2021 (the vulnerability was patched in SMR Mar-2021 Release 1)
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Assess kernel compromise statusReview running kernel modules and system integrity using forensic or security tools. This vulnerability requires an already compromised kernel as a prerequisite.Affected if Kernel compromise already exists (the HArx flaw only allows privilege escalation from an already compromised kernel to corrupt EL2 memory)
A Samsung mobile device running Android 10.0 or 11.0 with a security patch level earlier than March 2021, where the kernel is already compromised, is affected by this vulnerability.
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 dataUpdate Samsung mobile devices to SMR Mar-2021 Release 1 or later to obtain the vendor patch addressing the address validation flaw.
- Consultation2.0 h
- Implementation1.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,696.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-25339 — 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-2021-25339 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
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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