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CVE Record

CVE-2025-4382: Grub2: grub allow access to encrypted device through cli once root device is unlocked via tpm

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.

MediumCVSS 5.9Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

This flaw can undermine disk encryption on specially configured systems when an attacker has physical access. If GRUB automatically unlocks a LUKS disk through the TPM, filesystem corruption can force rescue mode after decryption, potentially exposing readable data without additional authentication and risking unauthorized modification.

Executive priority

Prioritize systems that are portable, unattended, deployed in accessible locations, or contain sensitive regulated data. This is not an internet-scale emergency, but affected configurations weaken a foundational encryption control. Expedite vendor review and remediation where realistic physical access could produce material data exposure.

Technical view

GRUB loads the TPM-held LUKS decryption key and unlocks the root device before confirming that its filesystem is usable. A corrupted superblock can make filesystem discovery fail and invoke rescue mode while the device remains decrypted and key material remains in memory. The reported impact is high confidentiality and integrity loss, with no availability impact.

Likely exposure

Exposure requires LUKS disk encryption, GRUB TPM-based automatic decryption, and attacker physical access sufficient to corrupt the underlying filesystem. The bundle marks Red Hat Enterprise Linux 7, 8, 9, and 10, plus OpenShift Container Platform 4, as affected. Systems without this configuration are unlikely to meet the described conditions.

Exploitation context

The CVSS score is 5.9 with physical attack vector, low complexity, and no user interaction. The bundle states that CISA KEV status is false and provides no evidence of active exploitation. Practical abuse depends on local physical access and a narrowly defined boot and encryption configuration.

Researcher notes

The weakness aligns with missing authentication after TPM-assisted decryption and rescue-mode entry. The supplied upstream GRUB diff indicates code-level remediation activity, but the bundle does not identify fixed downstream package versions or confirm backports. Validation should focus on configuration and vendor package status, not destructive exploitation.

Mitigation direction

  • Check Red Hat guidance for applicable fixed packages or supported mitigations.
  • Apply vendor-provided GRUB updates after testing boot and recovery behavior.
  • Restrict physical access to exposed endpoints, servers, and removable storage interfaces.
  • Review whether TPM automatic disk unlocking is necessary for each affected system.
  • Maintain tested backups to address potential filesystem integrity damage.

Validation and detection

  • Inventory systems using GRUB, LUKS, and TPM-based automatic root-device unlocking.
  • Map installed Red Hat and OpenShift versions against current vendor advisories.
  • Verify installed GRUB package versions after applying vendor-provided updates.
  • Confirm physical security controls for portable, remote, and unattended systems.
  • Avoid destructive reproduction on production disks; use isolated test systems if vendor guidance requires testing.
Prepared
Confidence
high
Sources
5

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · medium confidence lookup

CWE-306: Credential and account abuse lookup

Authentication and credential weaknesses can make valid-account abuse and credential telemetry useful review starting points. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

Open ATT&CK lookup
description · low confidence lookup

Container behavior lookup

The affected technology mentions containers, so container-specific ATT&CK technique review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2025-4382 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
Medium
CVSS
5.9 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:P/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

1CVSS vectors
5Timeline events
1ADP providers
4Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: total

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
5.9CVSS 3.1MediumCVSS:3.1/AV:P/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N0.75.2redhat

Vulnerability scoring details

Base CVSS 3.1 score

5.9Medium
CVSS 3.1 vector shape for CVE-2025-4382Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:P/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. Source timelineredhat

    Reported to Red Hat.

  3. Source timelineredhat

    Made public.

  4. CVE publishedCVE Program

    The CVE record was published.

  5. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
Unknown vendorgrub2grub2, 0unaffected
Red HatRed Hat Enterprise Linux 10grub2affected
Red HatRed Hat Enterprise Linux 7grub2affected
Red HatRed Hat Enterprise Linux 8grub2affected
Red HatRed Hat Enterprise Linux 9grub2affected
Red HatRed Hat OpenShift Container Platform 4openshift/ose-rhel-coreos-9affected
Weakness

CWE details

CWE-306

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.