CVE-2023-21455
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 authorization implementation in Exynos baseband prior to SMR Mar-2023 Release 1 allows incorrect handling of unencrypted message.
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 authorization in Samsung Exynos baseband modem firmware allows incorrect handling of unencrypted messages, potentially enabling code execution or privilege escalation at the baseband processor level (below the application processor OS). This critical flaw affects cellular communication security and could allow attackers to compromise the modem firmware through malformed or specially crafted unencrypted messages.
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
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
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 Exynos baseband modem usageCheck device specifications or settings to confirm the device uses an Exynos chipset with an Exynos baseband modem (found in Settings > About Phone or manufacturer's specs)Affected if Device does not use an Exynos baseband modem - different chipset vendors have separate firmware and patching cycles
-
Check baseband firmware versionNavigate to Settings > About Phone > Software Information and locate the 'Baseband' or 'Modem' version entry; alternatively, use *#1234# or *#*#1234#*#* on dialer to access service modeAffected if Baseband version shows any version number (all versions of Exynos baseband firmware prior to the patch are affected)
-
Verify security patch levelNavigate to Settings > About Phone > Software Information > Security patch level and note the date shown (format is typically YYYY-MM-01)Affected if Security patch level is earlier than March 2023 (e.g., February 2023 or older) - indicating the SMR Mar-2023 release has not been applied
User is affected if the device uses an Exynos baseband modem AND the security patch level is before March 2023 or the baseband version has not been updated to include the patched firmware.
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 · scopedApply Samsung's SMR (Security Maintenance Release) Mar-2023 Release 1 or later, which includes the patched baseband firmware. Users should check with their device manufacturer/carrier for availability of this update.
SMR Mar-2023 Release 1 or later
- Update the device firmware to SMR Mar-2023 Release 1 or later via Settings > Software Update
- Ensure the baseband firmware is updated as part of the system update (this may occur automatically over OTA)
- Verify the update was applied by checking the baseband version in Settings > About Phone > Software Information > Baseband version
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation8.0 h
- Implementation16.0 h
- Testing24.0 h
- Review / QA12.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $16,384.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-21455 — 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-2023-21455 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