dbcve.org
AndroidOperating system · Samsung

CVE-2023-21473

MEDIUM · 6.8 CVSS v3.1 Published 2025-09-03
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
68/100
Remediation priority · Elevated

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 · unedited
Improper input validation with Exynos Fastboot USB Interface prior to SMR Apr-2023 Release 1 allows a physical attacker to execute arbitrary code in bootloader.

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 confidence

Improper input validation in the Exynos Fastboot USB Interface allows a physical attacker with USB access to execute arbitrary code in the bootloader context. The vulnerability exists in the USB fastboot protocol handler within Samsung's Exynos bootloader prior to the April 2023 security patch.

MitigationApply the SMR Apr-2023 Release 1 or later security update for affected Exynos devices to patch the input validation flaw in the bootloader USB interface.

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
AndroidOperating system
Affected:= 11.0= 12.0= 13.0

CVSS 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
High
Privileges
High
User interaction
Required
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:P/AC:H/PR:H/UI:R/S:C/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 checks

Work through these to decide whether this CVE applies to you.

  1. Confirm Exynos chipset usage
    Check device specifications or run 'getprop ro.hardware' or 'getprop ro.board.platform' in ADB shell to identify the chipset. Exynos variants typically show 'exynos' in the hardware or platform properties.
    Affected if The device does not use an Exynos chipset (this vulnerability only affects Exynos-based Samsung devices).
  2. Verify Android version
    Run 'getprop ro.build.version.release' in ADB shell or check Settings > About Phone > Android version.
    Affected if The Android version is 11.0, 12.0, or 13.0 and the security patch level is earlier than April 2023.
  3. Check security patch level
    Run 'getprop ro.build.version.security_patch' in ADB shell or check Settings > About Phone > Security patch level.
    Affected if The security patch level is earlier than April 2023 (the SMR Apr-2023 Release 1 or later contains the fix).
  4. Confirm USB debugging or developer mode enabled
    Check Settings > Developer Options > USB Debugging is enabled, or verify 'getprop persist.sys.usb.config' includes 'adb' or 'fastboot'.
    Affected if USB debugging or fastboot mode is enabled and the device is connected to an untrusted USB port - this is the attack vector.
  5. Identify bootloader version
    Boot into fastboot mode (power + volume down) and run 'fastboot getvar version-bootloader' or check 'getprop ro.bootloader' in recovery/bootloader context.
    Affected if The bootloader version is from an older release predating the April 2023 security update.

A device is affected if it uses an Exynos chipset, runs Android 11.0/12.0/13.0, has a security patch level before April 2023, and has USB debugging or fastboot mode accessible - the physical USB access combined with the unpatched bootloader enables arbitrary code execution in the bootloader context.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the SMR Apr-2023 Release 1 or later security update for affected Exynos devices to patch the input validation flaw in the bootloader USB interface.

Recommended fix High confidence

SMR Apr-2023 Release 1 (April 2023 Samsung Security Patch)

  1. 1. Identify if the device is a Samsung device with an Exynos chipset (these are typically Samsung's in-house processors used in some Galaxy S, Galaxy A, and other models)
  2. 2. Check the current Android version and security patch level on the device (Settings > About Phone > Software Information > Security patch level)
  3. 3. Verify if the device has received the SMR Apr-2023 Release 1 security update or later
  4. 4. If the device has not received the update, check for available system updates through Settings > Software Update > Download and install
  5. 5. Apply any available Samsung security updates to address the improper input validation vulnerability in the Exynos Fastboot USB Interface
  6. 6. After updating, confirm the security patch level reflects April 2023 or later

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Android Scoped from the published advisory
  • Consultation8.0 h
  • Implementation24.0 h
  • Testing12.0 h
  • Review / QA8.0 h
52.0 hours of engineering $9,160
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2023-21473 in production — separate from our analysis above.

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What this is

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.

What belongs here
  • 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