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NVD / CVE Program· CNA Linux

CVE-2021-47228: x86/ioremap: Map EFI-reserved memory as encrypted for SEV

Noroxi assessment

Priority: Monitor (action score 24/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.23% (FIRST EPSS).
  • Someone with local access to the system can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 208bb686e7fa7fff16e8fa78ff0db34aa9acdbd7, 8d651ee9c71bb12fc0c8eb2786b66cbe5aa3e43b, b7a05aba39f733ec337c5b952e112dd2dc4fc404.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 208bb686e7fa7fff16e8fa78ff0db34aa9acdbd7, 8d651ee9c71bb12fc0c8eb2786b66cbe5aa3e43b, b7a05aba39f733ec337c5b952e112dd2dc4fc404 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: x86/ioremap: Map EFI-reserved memory as encrypted for SEV Some drivers require memory that is marked as EFI boot services data. In order for this memory to not be re-used by the kernel after ExitBootServices(), efi_mem_reserve() is used to preserve it by inserting a new EFI memory descriptor and marking it with the EFI_MEMORY_RUNTIME attribute. Under SEV, memory marked with the EFI_MEMORY_RUNTIME attribute needs to be mapped encrypted by Linux, otherwise the kernel might crash at boot like below: EFI Variables Facility v0.08 2004-May-17 general protection fault, probably for non-canonical address 0x3597688770a868b2: 0000 [#1] SMP NOPTI CPU: 13 PID: 1 Comm: swapper/0 Not tainted 5.12.4-2-default #1 openSUSE Tumbleweed Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:efi_mokvar_entry_next [...] Call Trace: efi_mokvar_sysfs_init ? efi_mokvar_table_init do_one_initcall ? __kmalloc kernel_init_freeable ? rest_init kernel_init ret_from_fork Expand the __ioremap_check_other() function to additionally check for this other type of boot data reserved at runtime and indicate that it should be mapped encrypted for an SEV guest. [ bp: Massage commit message. ]

MediumCVSS 6.2 · v3.1—No exploit Fix available
Published
May 21, 2024
Updated
Jun 17, 2026
EPSS
0.2% · 14th percentile
CWE
—

Report tools

JSON

Action score

24

Monitor

Low priority for now.

CVSS
24 / 40 · 6.2 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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When you'll hear from us

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  • when exploit code appears or is weaponized
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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel5.10 and later · before 5.10.46
  • linux linux kernel5.11 and later · before 5.12.13
  • linux linux kernel5.13

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 5.10affected
    • 58c909022a5a56cd1d9e89c8c5461fd1f6a27bb5 and later · before 208bb686e7fa7fff16e8fa78ff0db34aa9acdbd7affected · git
    • 58c909022a5a56cd1d9e89c8c5461fd1f6a27bb5 and later · before b7a05aba39f733ec337c5b952e112dd2dc4fc404affected · git
    • 58c909022a5a56cd1d9e89c8c5461fd1f6a27bb5 and later · before 8d651ee9c71bb12fc0c8eb2786b66cbe5aa3e43baffected · git
    • before 5.10not affected · semver
    • 5.10.46 and later · up to and including 5.10.*not affected · semver
    • 5.12.13 and later · up to and including 5.12.*not affected · semver
    • 5.13 and laternot affected · original_commit_for_fix

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 5.10.46-15.10.46-1
SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSSkernel-64kbbefore 5.3.18-150300.59.164.15.3.18-150300.59.164.1
SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSSkernel-default-basebefore 5.3.18-150300.59.164.1.150300.18.96.15.3.18-150300.59.164.1.150300.18.96.1
SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSSkernel-docsbefore 5.3.18-150300.59.164.15.3.18-150300.59.164.1
SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSSkernel-obs-buildbefore 5.3.18-150300.59.164.15.3.18-150300.59.164.1
SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSSkernel-preemptbefore 5.3.18-150300.59.164.15.3.18-150300.59.164.1
SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSSkernel-sourcebefore 5.3.18-150300.59.164.15.3.18-150300.59.164.1
SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSSkernel-symsbefore 5.3.18-150300.59.164.15.3.18-150300.59.164.1
SUSE:Linux Enterprise Live Patching 15 SP3kernel-defaultbefore 5.3.18-150300.59.164.15.3.18-150300.59.164.1
SUSE:Linux Enterprise Live Patching 15 SP3kernel-livepatch-SLE15-SP3_Update_45before 1-150300.7.3.11-150300.7.3.1
SUSE:Linux Enterprise Micro 5.1kernel-rtbefore 5.3.18-150300.172.15.3.18-150300.172.1
SUSE:Linux Enterprise Micro 5.1kernel-source-rtbefore 5.3.18-150300.172.15.3.18-150300.172.1
SUSE:Linux Enterprise Server 15 SP3-LTSSkernel-zfcpdumpbefore 5.3.18-150300.59.164.15.3.18-150300.59.164.1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe…KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2021-47226May 21, 2024 · x86/fpu: Invalidate FPU state after a failed XRSTOR from a user buffer
    28Monitor
  • ← EarlierCVE-2021-47227May 21, 2024 · x86/fpu: Prevent state corruption in __fpu__restore_sig()
    22Monitor
  • Later →CVE-2021-47229May 21, 2024 · PCI: aardvark: Fix kernel panic during PIO transfer
    22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux208bb686e7fa7fff16e8fa78ff0db34aa9acdbd7Vendor (CNA)
Linux Linux8d651ee9c71bb12fc0c8eb2786b66cbe5aa3e43bVendor (CNA)
Linux Linuxb7a05aba39f733ec337c5b952e112dd2dc4fc404Vendor (CNA)
debian:linux5.10.46-1 · Debian:12Package registry (OSV)
suse:kernel-64kb5.3.18-150300.59.164.1 · SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSSPackage registry (OSV)
suse:kernel-default5.3.18-150300.59.164.1 · SUSE:Linux Enterprise Live Patching 15 SP3Package registry (OSV)
suse:kernel-default-base5.3.18-150300.59.164.1.150300.18.96.1 · SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSSPackage registry (OSV)
suse:kernel-docs5.3.18-150300.59.164.1 · SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSSPackage registry (OSV)
suse:kernel-livepatch-SLE15-SP3_Update_451-150300.7.3.1 · SUSE:Linux Enterprise Live Patching 15 SP3Package registry (OSV)
suse:kernel-obs-build5.3.18-150300.59.164.1 · SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSSPackage registry (OSV)
suse:kernel-preempt5.3.18-150300.59.164.1 · SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSSPackage registry (OSV)
suse:kernel-rt5.3.18-150300.172.1 · SUSE:Linux Enterprise Micro 5.1Package registry (OSV)
suse:kernel-source5.3.18-150300.59.164.1 · SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSSPackage registry (OSV)
suse:kernel-source-rt5.3.18-150300.172.1 · SUSE:Linux Enterprise Micro 5.1Package registry (OSV)
suse:kernel-syms5.3.18-150300.59.164.1 · SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSSPackage registry (OSV)
suse:kernel-zfcpdump5.3.18-150300.59.164.1 · SUSE:Linux Enterprise Server 15 SP3-LTSSPackage registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

—

CVSS vector

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

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (2 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records