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Incorrect Default PermissionsWeakness · CWE-276

CVE-2024-21820

HIGH · 7.2 CVSS v3.1 Published 2024-11-13
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
74/100
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
Incorrect default permissions in some Intel(R) Xeon(R) processor memory controller configurations when using Intel(R) SGX may allow a privileged user to potentially enable escalation of privilege via local access.

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

Intel Xeon processor memory controllers have incorrect default permissions when Intel SGX (Software Guard Extensions) is enabled, allowing a locally authenticated privileged user to escalate their privileges. The vulnerability stems from improper permission configurations in the memory controller that can be exploited through local access.

MitigationApply Intel-provided firmware/BIOS updates for affected Xeon processors and review memory controller permission settings when SGX is enabled. As a temporary workaround, consider disabling SGX if not required, or ensure strict access controls to systems with SGX-enabled configurations.

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
Local
Complexity
High
Privileges
High
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
None

CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/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. Identify Intel Xeon processor in use
    Run 'lscpu | grep -i xeon' on Linux or check System Information on Windows to confirm an Intel Xeon CPU is installed
    Affected if System does not have an Intel Xeon processor, then not affected by this specific vulnerability
  2. Check if Intel SGX is enabled
    On Linux, run 'ls /dev/sgx*' or check BIOS/UEFI settings for Software Guard Extensions (SGX) status. On Windows, check 'sgx-get-capacity' or BIOS settings. Some systems also show SGX status via 'dmesg | grep -i sgx'
    Affected if SGX is disabled or not available on the system, then the vulnerability path does not apply
  3. Verify firmware/BIOS version against Intel advisory
    Check system BIOS/UEFI version information (accessible via 'dmidecode -s bios-version' on Linux, or via System Information/DMI on Windows) and compare against Intel's published affected version ranges for this CVE
    Affected if Firmware version matches an affected version range AND SGX is enabled, then system is likely vulnerable
  4. Confirm local privileged access context
    Verify the user context: this vulnerability requires a locally authenticated privileged user to exploit. Check current user privileges with 'whoami' and 'id' on Linux or 'whoami /all' on Windows
    Affected if Exploit requires local authenticated privileged user access; unprivileged or remote attackers cannot leverage this specific flaw

System is affected if it runs an Intel Xeon processor with SGX enabled and has a firmware version within the affected range published by Intel for this CVE.

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 Intel-provided firmware/BIOS updates for affected Xeon processors and review memory controller permission settings when SGX is enabled. As a temporary workaround, consider disabling SGX if not required, or ensure strict access controls to systems with SGX-enabled configurations.

Recommended fix Moderate confidence

Latest Intel Xeon processor firmware/BIOS that includes the fix for CVE-2024-21820 (contact Intel or OEM for the specific version)

  1. Identify the exact Intel Xeon processor model and current BIOS/firmware version.
  2. Locate Intel's security advisory for CVE-2024-21820 (or the related Intel Xeon SGX memory controller advisory) to determine the required firmware version.
  3. Obtain the corresponding firmware/BIOS update from Intel or the system vendor (OEM).
  4. Apply the firmware update using the vendor's recommended procedure (e.g., BIOS flash tool, BMC firmware update).
  5. Reboot the system and verify that Intel SGX is enabled with correct memory controller permissions.
Caveat Firmware updates may cause downtime and reset BIOS settings; back up configuration before updating.

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

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-2024-21820 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
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  • Version or environment caveats, and links to real fixes
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