CVE-2021-47134

Boot-time kernel panic via missing valid FDT

Published Mar 15, 2024 · Updated May 11, 2026

NULL pointer dereference in the Linux kernel allows local users to trigger a kernel panic during RISC-V EFI boot without a valid FDT. Architecture setup continues FDT processing after efi_get_fdt_params finds no valid FDT, leaving initial_boot_params null for later dereference. Reachability requires the affected RISC-V EFI boot path and an absent or invalid FDT; the documented consequence is boot failure and service interruption.

CVSS severity5.5
Medium
EPSS probability0.23%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

NULL pointer dereference in the Linux kernel allows local users to trigger a kernel panic during RISC-V EFI boot without a valid FDT. Architecture setup continues FDT processing after efi_get_fdt_params finds no valid FDT, leaving initial_boot_params null for later dereference. Reachability requires the affected RISC-V EFI boot path and an absent or invalid FDT; the documented consequence is boot failure and service interruption.

The record

CVE
CVE-2021-47134
Published
Mar 15, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 15, 2024CVE publishedPublication date reported by the CVE source.
  2. May 11, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=5.10
  2. Affected versionversion=b91540d52a08b65eb6a2b09132e1bd54fa82754c <5148066edbdc89c6fe5bc419c31a5c22e5f83bdb
  3. Affected versionversion=b91540d52a08b65eb6a2b09132e1bd54fa82754c <668a84c1bfb2b3fd5a10847825a854d63fac7baa
  4. Affected versionversion=b91540d52a08b65eb6a2b09132e1bd54fa82754c <8a7e8b4e5631a03ea2fee27957857a56612108ca

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.10; version=b91540d52a08b65eb6a2b09132e1bd54fa82754c <5148066edbdc89c6fe5bc419c31a5c22e5f83bdb; version=b91540d52a08b65eb6a2b09132e1bd54fa82754c <668a84c1bfb2b3fd5a10847825a854d63fac7baa; version=b91540d52a08b65eb6a2b09132e1bd54fa82754c <8a7e8b4e5631a03ea2fee27957857a56612108ca

Published CVSS scores

5.5CVECVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo