CVE-2020-8569: Kubernetes CSI snapshot-controller DoS

Recommended actionWithin 7 days

Medium technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.

Fix not verified

What, why and how

Kubernetes CSI snapshot-controller prior to v2.1.3 and v3.0.2 could panic when processing a VolumeSnapshot custom resource when: - The VolumeSnapshot referenced a non-existing PersistentVolumeClaim and the VolumeSnapshot did not reference any VolumeSnapshotClass. - The snapshot-controller crashes, is automatically restarted by Kubernetes, and processes the same VolumeSnapshot custom resource after the restart, entering an endless crashloop. Only the volume snapshot feature is affected by this vulnerability. When exploited, users can’t take snapshots of their volumes or delete the snapshots. All other Kubernetes functionality is not affected.

What

Why

The product dereferences a pointer that it expects to be valid but is NULL.

How

An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may disrupt the affected service.

What

Why

The product dereferences a pointer that it expects to be valid but is NULL.

How

An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may disrupt the affected service.

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation

Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.

No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material

Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.

Reference recorded

A structured CVE source labels at least one public reference as exploit material. BlackTree has not independently validated that it is safe, reliable or weaponised.

Likely attack path: a network path → NULL Pointer Dereference → disrupt the affected service
Attack surface: Network
Privileges required: Low: a basic authenticated account is required
User interaction: None
Attack complexity: Low: no specialised conditions are recorded
Security boundary: Unchanged: impact remains within the vulnerable component's security authority
Weakness ? CWE means Common Weakness Enumeration: a standard category for the underlying weakness.: CWE-476 ↗
CWE-476: NULL Pointer Dereference. The product dereferences a pointer that it expects to be valid but is NULL.
CVSS vector ? CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.INoneIntegrity impact: No direct loss is represented by this metric.ALowAvailability impact: A successful attack can cause a limited loss.
Post-exploitation / living off the land: No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.

NetworkDenial of serviceCWE-476Public exploit reference

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

ENISA EUVD · EUVD-2022-1057Official EUVD mapping

0 linked advisory records.

Official EUVD record ↗

Cyber Security Agency of Singapore · English · CSA-SB-20210127Security Bulletin 27 Jan 2021

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 27 Jan 2021, published on 27 January 2021. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗

JVN iPedia · Japanese · JVNDB-2020-015708Kubernetes CSI snapshot-controller における NULL ポインタデリファレンスに関する脆弱性

Kubernetes CSI snapshot-controller には、NULL ポインタデリファレンスに関する脆弱性が存在します。

Official advisory ↗

Patch and workaround

Operational remediation based on structured source evidence.

Status ? Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.: Fix not verified
Affected: CSI Snapshotter: snapshot-controller v3.0 ≤ v3.0.1, snapshot-controller v2.1 ≤ v2.1.2
Fixed: No fixed version is explicitly recorded in the structured CVE data.
Action: No verified patch reference is present in the current structured sources. Check the vendor advisory before making a change.
Workaround: No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.

Evidence and provenance

Published 21 Jan 2021 · Last source change 17 Sept 2024, 01:47 UTC · CWE-476 · NULL Pointer Dereference

CVE recordCVE.org · 5.1

CVSS sourceCNA

EPSS source

The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.

FIRST · tracked since 2026-08-14

European sourceENISA EUVD · EUVD-2022-1057

Product sourceCNA

Remediation sourceCVE/CNA references

CWE sourceCNA

NVD statusNVD modified after enrichment

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

2021-01-21CVE published

ENISA EUVD · EUVD-2022-1057↗CVE authority or vendor reference↗Public exploit reference↗Official CVE record (CNA and ADP data)↗NVD record↗

Technical terms and abbreviations used in this report

CVE: Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS: Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS: Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE: Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA: CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP: Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD: National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT: A computer security incident response team that publishes warnings or coordinates incident response.
PoC: Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF: Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL: Living off the land: abuse of legitimate tools or system functions during an attack.

Kubernetes CSI snapshot-controller DoS

Published severity in operational context

Evidence used

Compensating controls

Verification

National CERT insights
?
CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

ENISA European Vulnerability Database

EUVD-2022-1057