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NVD / CVE Program· CNA Linux

CVE-2021-47389: KVM: SVM: fix missing sev_decommission in sev_receive_start

MediumCVSS 5.1 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 20/100)

  • 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: 0.21% (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 efd7866e114dcb44f86d151e843f8276b7efbc67, f1815e0aa770f2127c5df31eb5c2f0e37b60fa77.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux efd7866e114dcb44f86d151e843f8276b7efbc67, f1815e0aa770f2127c5df31eb5c2f0e37b60fa77 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: KVM: SVM: fix missing sev_decommission in sev_receive_start DECOMMISSION the current SEV context if binding an ASID fails after RECEIVE_START. Per AMD's SEV API, RECEIVE_START generates a new guest context and thus needs to be paired with DECOMMISSION: The RECEIVE_START command is the only command other than the LAUNCH_START command that generates a new guest context and guest handle. The missing DECOMMISSION can result in subsequent SEV launch failures, as the firmware leaks memory and might not able to allocate more SEV guest contexts in the future. Note, LAUNCH_START suffered the same bug, but was previously fixed by commit 934002cd660b ("KVM: SVM: Call SEV Guest Decommission if ASID binding fails").

Published
May 21, 2024
Updated
Jun 17, 2026
EPSS
0.2% · 11th percentile

Report tools

JSON

Action score

20

Monitor

Low priority for now.

CVSS
20 / 40 · 5.1 / 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.

Follow CVE-2021-47389

When you'll hear from us

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  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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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

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

    • 5.13affected
    • af43cbbf954b50ca97d5e7bb56c2edc6ffd209ef and later · before efd7866e114dcb44f86d151e843f8276b7efbc67affected · git
    • af43cbbf954b50ca97d5e7bb56c2edc6ffd209ef and later · before f1815e0aa770f2127c5df31eb5c2f0e37b60fa77affected · git
    • before 5.13not affected · semver
    • 5.14.10 and later · up to and including 5.14.*not affected · semver
    • 5.15 and laternot affected · original_commit_for_fix

Affected versions

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

  • linux linux kernel5.13 and later · before 5.14.10
  • linux linux kernel5.15

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 5.14.12-15.14.12-1

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-2021-47387May 21, 2024 · cpufreq: schedutil: Use kobject release() method to free sugov_tunables
    22Monitor
  • ← EarlierCVE-2021-47388May 21, 2024 · mac80211: fix use-after-free in CCMP/GCMP RX
    31Monitor
  • Later →CVE-2021-47390May 21, 2024 · KVM: x86: Fix stack-out-of-bounds memory access from ioapic_write_indirect()
    28Monitor

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 Linuxefd7866e114dcb44f86d151e843f8276b7efbc67Vendor (CNA)
Linux Linuxf1815e0aa770f2127c5df31eb5c2f0e37b60fa77Vendor (CNA)
debian:linux5.14.12-1 · Debian:12Package 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.

Variant candidates

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

  • CVE-2022-50189393 days aparttools/power turbostat: Fix file pointer leak
    28Monitor
  • CVE-2021-472830 days apartnet:sfc: fix non-freed irq in legacy irq mode
    22Monitor
  • CVE-2024-358214 days apartubifs: Set page uptodate in the correct place
    22Monitor
  • CVE-2024-47733153 days apartnetfs: Delete subtree of 'fs/netfs' when netfs module exits
    22Monitor
  • CVE-2024-53074182 days apartwifi: iwlwifi: mvm: don't leak a link on AP removal
    22Monitor
  • CVE-2023-22996448 days apartIn the Linux kernel before 5.17.2, drivers/soc/qcom/qcom_aoss.c does not release an of_find_device_by_node reference after use, e.g., with…
    22Monitor

National notice (Türkiye Cybersecurity Directorate / USOM)

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

All national notices →

Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit · public bounty program.

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
low · data or configuration can be modified
Availability
low · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
Low
Availability impact
Low

Weakness class (CWE)

CWE-772 · Missing Release of Resource after Effective Lifetime

CVSS vector

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

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.

Attack patterns (CAPEC)

References

Show all references (1 more)

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

All records