TizenOperating system · Linux
CVE-2021-25436
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 input validation vulnerability in Tizen FOTA service prior to Firmware update JUL-2021 Release allows arbitrary code execution via Samsung Accessory Protocol.
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 input validation in the Tizen FOTA (Firmware Over-The-Air) service allows attackers to achieve arbitrary code execution through the Samsung Accessory Protocol. The vulnerability stems from the service failing to properly sanitize or validate inputs received via this protocol, enabling remote code execution without authentication.
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
TizenOperating system
< 5.5CVSS 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
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/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.
-
Identify Tizen versionCheck the installed Tizen OS version on the device (typically via system settings, /etc/os-release, or tizen-id command)Affected if The Tizen version is Linux Tizen below version 5.5
-
Locate FOTA serviceIdentify whether the FOTA (Firmware Over-The-Air) service is present and running on the systemAffected if The FOTA service is installed and running on the device
-
Verify Samsung Accessory Protocol statusDetermine if the Samsung Accessory Protocol module or service is enabled on the deviceAffected if The Samsung Accessory Protocol is enabled or accessible on the device
-
Inspect FOTA input handlingExamine FOTA service configuration or logs for any custom input validation settings related to the Samsung Accessory ProtocolAffected if Custom input validation for the Samsung Accessory Protocol is configured or the service accepts external inputs from this protocol
The device is affected if it runs Linux Tizen version below 5.5 and has the FOTA service with Samsung Accessory Protocol enabled.
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.
dbcve · scoped5.5
Apply the JUL-2021 or later firmware update for Tizen devices to patch the improper input validation vulnerability in the FOTA service.
Tizen 5.5 or JUL-2021 firmware release
- Identify the specific Tizen device model affected
- Check the current firmware version on the device
- Apply the JUL-2021 Firmware update released by Samsung for the specific device model
- Verify the firmware update was successfully applied
- Confirm the Tizen version is now 5.5 or later
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Tizen
Scoped from the published advisory
- Consultation8.0 h
- Implementation16.0 h
- Testing12.0 h
- Review / QA8.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $12,352.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-25436 — 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-2021-25436 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