U BootApplication · Denx

CVE-2017-3226

MEDIUM · 6.4 CVSS v3.0 Published 2018-07-24
Fix available
A fix is available. Upgrade to 2017.09 or later.
See remediation →
69/100
Remediation priority · Elevated
No privileges Zero-click

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
Das U-Boot is a device bootloader that can read its configuration from an AES encrypted file. Devices that make use of Das U-Boot's AES-CBC encryption feature using environment encryption (i.e., setting the configuration parameter CONFIG_ENV_AES=y) read environment variables from disk as the encrypted disk image is processed. An attacker with physical access to the device can manipulate the encrypted environment data to include a crafted two-byte sequence which triggers an error in environment variable parsing. This error condition is improperly handled by Das U-Boot, resulting in an immediate process termination with a debugging 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 confidence

Das U-Boot's AES-CBC encrypted environment feature (CONFIG_ENV_AES) contains improper error handling when parsing encrypted environment variables. An attacker with physical access can manipulate the encrypted environment data with a crafted two-byte sequence that triggers a parsing error. This error condition is not handled properly, causing immediate process termination with a debugging message.

MitigationUpgrade Das U-Boot to a version that properly handles parsing errors in encrypted environments. Until patched, limit physical access to devices using CONFIG_ENV_AES to prevent manipulation of encrypted environment data.

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
U BootApplication
Affected:< 2017.09

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
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.0/AV:P/AC:H/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 checks

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

  1. Identify the U-Boot version
    Check the U-Boot version string displayed during boot, or run 'version' or 'bootz' commands in the U-Boot console, or examine the bootloader binary file for version information
    Affected if The version is earlier than 2017.09 (for example, 2017.01, 2016.11, etc.)
  2. Verify CONFIG_ENV_AES is enabled
    Inspect the U-Boot configuration file (.config) or build settings used when compiling the bootloader; look for CONFIG_ENV_AES defined, or check if the 'env' command supports AES decryption options
    Affected if CONFIG_ENV_AES is present and enabled in the U-Boot build configuration
  3. Confirm encrypted environment is in use
    Check if the target device stores an encrypted environment; examine the boot arguments, environment partition, or U-Boot configuration for references to encrypted env storage (for example, CONFIG_ENV_IS_IN_FLASH with encryption, or CONFIG_ENV_ADDR indicating encrypted location)
    Affected if The device uses encrypted environment storage (not plain text environment variables) and the U-Boot version is before 2017.09
  4. Check for debugging output on boot
    Observe the console output during U-Boot initialization; look for any error messages, assertion failures, or debugging strings related to AES decryption or environment parsing that appear before the boot process halts
    Affected if Debugging messages related to AES/environment parsing errors appear and the boot process terminates unexpectedly

The environment is affected if the device runs Das U-Boot version before 2017.09 with CONFIG_ENV_AES enabled and encrypted environment storage in use.

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.

From vendor data
Upgrade available Upgrade to 2017.09 or later
Fixed in 2017.09
Interim mitigation

Upgrade Das U-Boot to a version that properly handles parsing errors in encrypted environments. Until patched, limit physical access to devices using CONFIG_ENV_AES to prevent manipulation of encrypted environment data.

Fix this in U Boot Scoped from the published advisory
  • Consultation2.0 h
  • Implementation6.0 h
  • Testing4.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,440
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,904.

Scan for this in your stack

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dbcve dependency scanner

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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-2017-3226 in production — separate from our analysis above.

No notes yet

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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