Missing AuthenticationWeakness · CWE-306

CVE-2025-4382

MEDIUM · 5.9 CVSS v3.1 Published 2025-05-09
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
61/100
Remediation priority · Elevated
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
A flaw was found in systems utilizing LUKS-encrypted disks with GRUB configured for TPM-based auto-decryption. When GRUB is set to automatically decrypt disks using keys stored in the TPM, it reads the decryption key into system memory. If an attacker with physical access can corrupt the underlying filesystem superblock, GRUB will fail to locate a valid filesystem and enter rescue mode. At this point, the disk is already decrypted, and the decryption key remains loaded in system memory. This scenario may allow an attacker with physical access to access the unencrypted data without any further authentication, thereby compromising data confidentiality. Furthermore, the ability to force this state through filesystem corruption also presents a data integrity concern.

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

In systems using LUKS-encrypted disks with GRUB configured for TPM-based automatic decryption, an attacker with physical access can corrupt the filesystem superblock to force GRUB into rescue mode. Since the disk auto-decrypts early in the boot process, the decryption key remains loaded in memory even after GRUB enters rescue mode, allowing access to decrypted data without authentication.

MitigationDisable TPM-based automatic decryption and require manual authentication (passphrase) or implement additional authentication layers before data access. Alternatively, ensure physical security to prevent filesystem corruption attacks.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

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

CVSS:3.1/AV:P/AC:L/PR:L/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 checks

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

  1. Verify LUKS encryption is in use
    Run 'lsblk -o NAME,TYPE,FSTYPE' or check 'cryptsetup luksDump /dev/sdX' for each disk to confirm LUKS header
    Affected if Any system disk uses LUKS encryption (TYPE='crypt' in lsblk or luksDump succeeds)
  2. Check GRUB configuration for TPM auto-unlock
    Inspect /boot/grub/grub.cfg for 'tpm2' or 'unlock' keywords, or grep for TPM in /etc/default/grub and /etc/grub.d/* files
    Affected if GRUB contains TPM-related automatic decryption configuration (e.g., 'tpm2-auto-unlock' or similar settings)
  3. Verify TPM unlock settings in crypttab
    Check /etc/crypttab for entries containing 'tpm2-device' or 'tpm2-key' options indicating TPM-based key retrieval
    Affected if Any crypttab entry specifies TPM-based automatic unlocking (not just passphrase or keyfile)
  4. Confirm TPM2 hardware or firmware is present
    Run 'ls /dev/tpm*' or 'tpm2_getcap handles-persistent' to detect TPM2 device availability
    Affected if TPM2 device is present and usable by the system for key storage

The system is affected if it uses LUKS encryption combined with TPM-based automatic decryption enabled in GRUB and crypttab, allowing the decryption key to remain in memory after GRUB rescue mode is triggered via filesystem corruption.

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

Disable TPM-based automatic decryption and require manual authentication (passphrase) or implement additional authentication layers before data access. Alternatively, ensure physical security to prevent filesystem corruption attacks.

Have this fixed Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
18.0 hours of engineering $3,200
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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-2025-4382 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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