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Full vulnerability report · 2021
CVE-2021-20206High confidence

An improper limitation of path name flaw was found in containernetworking/cni in versions before 0.8.1

Unknown · containernetworking-cni

7.2HighCVSS 3.1
Recommended action
Within 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Patch available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityHighOperational priority:High, unchanged from published severity.unchanged

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • EPSS is 1.52% for the current model date.

Compensating controls

  • Validate the affected product branch and deploy the verified fixed release.
  • Restrict the affected network interface to trusted sources where business-safe.
  • Monitor vendor guidance and exploitation sources for a material change.

Verification

  1. Confirm that the asset runs Unknown containernetworking-cni and falls inside the recorded affected range.
  2. Verify the installed build against the product-specific fixed version after deployment.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: Within 30 daysRemediation target: Within 180 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Distribution package intelligence

Release-specific package status

Alpine, Debian, ubuntu findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.

8 package states
Repository candidate not checked

A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.

Distribution releaseSource packageVendor stateFixed versionEvidence
Alpine v3.23v3.23 · communitybuildahVendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.1.19.4-r0Alpine Security Database ↗Source updated 11 Sep 2026
Alpine v3.22v3.22 · communitybuildahVendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.1.19.4-r0Alpine Security Database ↗Source updated 11 Sep 2026
Alpine v3.21v3.21 · communitybuildahVendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.1.19.4-r0Alpine Security Database ↗Source updated 19 Aug 2026
Debian trixietrixie · sourcegolang-github-appc-cniVendor fix publishedDebian records a fixed source-package version for this release.0.8.1-1Debian Security Tracker ↗Source updated 6 Oct 2026
Debian bookwormbookworm · sourcegolang-github-appc-cniVendor fix publishedDebian records a fixed source-package version for this release.0.8.1-1Debian Security Tracker ↗Source updated 6 Oct 2026
Debian forkyforky · sourcegolang-github-appc-cniVendor fix publishedDebian records a fixed source-package version for this release.0.8.1-1Debian Security Tracker ↗Source updated 6 Oct 2026
Debian sidsid · sourcegolang-github-appc-cniVendor fix publishedDebian records a fixed source-package version for this release.0.8.1-1Debian Security Tracker ↗Source updated 6 Oct 2026
Ubuntu 24.04 LTSnoble · standard archivegolang-github-appc-cniUnder evaluationCanonical reports that the package might be affected and still needs evaluation or fixing.Not published in this feedCanonical Ubuntu Security ↗Source updated 5 Oct 2026
Direct vendor intelligence

Authoritative vendor CSAF and VEX advisories

Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.

1 current
CVE-2021-20206 · CSAF 2.0 · revision 3 · finalRed Hat Product Securitycontainernetworking-cni: Arbitrary path injection via type field in CNI configuration
77 known affected

The vendor explicitly identifies these products as affected by this CVE.

  • servicemesh-cni as a component of OpenShift Service Mesh 2.0
  • servicemesh-cni.src as a component of OpenShift Service Mesh 2.0
  • buildah.src as a component of Red Hat Enterprise Linux 7
  • containernetworking-plugins.src as a component of Red Hat Enterprise Linux 7
  • podman.src as a component of Red Hat Enterprise Linux 7
  • buildah-tests (container-tools:1.0) as a component of Red Hat Enterprise Linux 8
  • buildah-tests (container-tools:2.0) as a component of Red Hat Enterprise Linux 8
  • buildah-tests (container-tools:rhel8) as a component of Red Hat Enterprise Linux 8
  • buildah.src (container-tools:1.0) as a component of Red Hat Enterprise Linux 8
  • buildah.src (container-tools:2.0) as a component of Red Hat Enterprise Linux 8
  • buildah.src (container-tools:rhel8) as a component of Red Hat Enterprise Linux 8
  • buildah (container-tools:1.0) as a component of Red Hat Enterprise Linux 8
Summary
An improper limitation of path name flaw was found in containernetworking/cni. When specifying the plugin to load in the `type` field in the network configuration, it is possible to use special elements such as "../" separators to reference binaries elsewhere on the system. This flaw allows an attacker to execute other existing binaries other than the cni plugins/types, such as `reboot`. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.
Remediation
For Windows Machine Config Operator upgrades, see the following documentation: https://docs.openshift.com/container-platform/latest/windows_containers/windows-node-upgrades.html
Optional official sources

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

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2022-1255

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Patch available
01

What, why and how

An improper limitation of path name flaw was found in containernetworking/cni in versions before 0.8.1. When specifying the plugin to load in the 'type' field in the network configuration, it is possible to use special elements such as "../" separators to reference binaries elsewhere on the system. This flaw allows an attacker to execute other existing binaries other than the cni plugins/types, such as 'reboot'. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.

What

An improper limitation of path name flaw was found in containernetworking/cni in versions before 0.8.1. When specifying the plugin to load in the 'type' field in the network configuration, it is possible to use special elements such as "../" separators to reference binaries elsewhere on the system. This flaw allows an attacker to execute other existing binaries other than the cni plugins/types, such as 'reboot'. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.

Why

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

How

An attacker operating through a network path may attempt exploitation with elevated privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

An improper limitation of path name flaw was found in containernetworking/cni in versions before 0.8.1. When specifying the plugin to load in the 'type' field in the network configuration, it is possible to use special elements such as "../" separators to reference binaries elsewhere on the system. This flaw allows an attacker to execute other existing binaries other than the cni plugins/types, such as 'reboot'. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.

Why

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

How

An attacker operating through a network path may attempt exploitation with elevated privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

02

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.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → Improper Input Validation → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
High: elevated access 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-20 ↗

CWE-20: Improper Input Validation. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

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:H/UI:N/S:U/C:H/I:H/A:H

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.PRHighPrivileges required: The attacker needs elevated or administrative privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major 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.
NetworkCWE-20
A

Official authority intelligence

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

BSI · German · WID-SEC-2022-0510IBM DB2: Mehrere Schwachstellen

Ein entfernter, anonymer, authentisierter oder lokaler Angreifer kann mehrere Schwachstellen in IBM DB2 ausnutzen, um Dateien zu manipulieren, Sicherheitsmaßnahmen zu umgehen, vertrauliche Informationen offenzulegen, einen Denial-of-Service-Zustand auszulösen, willkürlichen Code mit erhöhten Rechten auszuführen, Informationen falsch darzustellen und beliebigen Code auszuführen.

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20210331Security Bulletin 31 Mar 2021

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 31 Mar 2021, published on 31 March 2021. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2022-AVI-591Multiples vulnérabilités dans les produits IBM

.cve.org/CVERecord?id=CVE-2020-8551 Référence CVE CVE-2020-8552 https://www.cve.org/CVERecord?id=CVE-2020-8552 Référence CVE CVE-2020-8554 https://www.cve.org/CVERecord?id=CVE-2020-8554 Référence CVE CVE-2020-8555 https://www.cve.org/CVERecord?id=CVE-2020-8555 Référence CVE CVE-2020-8557 https://www.cve.org/CVERecord?id=CVE-2020-8557 Référence CVE CVE-2020-8559 https://www.cve.org/CVERecord?id=CVE-2020-8559 Référence CVE CVE-2020-8564 https://www.cve.org/CVERecord?id=CVE-2020-8564 Référence CVE CVE-2020-8565 https://www.cve.org/CVERecord?id=CVE-2020-8565 Référence CVE CVE-2020-9283 https://www.cve.org/CVERecord?id=CVE-2020-9283 Référence CVE CVE-2021-20206 https://www.cve.org/CVERecord?id=CVE-2021-20206 Référence CVE CVE-2021-20269 https://www.cve.org/CVERecord?id=CVE-2021-20269 Référence CVE CVE-2021-20321 https://www.cve.org/CVERecord?id=CVE-2021-20321 Référence CVE CVE-2021-20322 https://www.cve.org/CVERecord?id=CVE-2021-20322 Référence CVE CVE-2021-21781 https://www.cve.org/CVERecord?id=CVE-2021-21781 Référence CVE CVE-2021-25735 https://www.cve.org/CVERecord?id=CVE-2021-25735 Référence CVE CVE-2021-25736 https://www.cve.org/CVERecord?id=CVE-2021-25736 Référence CVE CVE-2021-25737 https://www.cve.org/CVERecord?id=CVE-2021-25737 Référence CVE CVE-2021-25741 https://www.cve.org/CVERecord?id=

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2021-004975containernetworking/cni におけるパストラバーサルの脆弱性

containernetworking/cni には、パストラバーサルの脆弱性が存在します。

Official advisory ↗
03

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.
Patch available
Affected
Fixed
Action
For Windows Machine Config Operator upgrades, see the following documentation: https://docs.openshift.com/container-platform/latest/windows_containers/windows-node-upgrades.html
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.
04

Evidence and provenance

Published 26 Mar 2021 · Last source change 3 Aug 2024, 17:30 UTC · CWE-20 · Improper Input Validation

CVE recordCVE.org · 5.1
CVSS sourceNIST NVD
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-2022-1255
Product sourceVendor CSAF · Red Hat Product Security
Remediation sourceVendor CSAF · Red Hat Product Security
CWE sourceCNA
NVD statusNVD modified after enrichment

Missing structured fields: affected product. Missing data is not evidence of low risk; review the primary advisory.

Material change intelligence

What changed after publication

View recent updates ↗
  1. Affected versionsThe structured affected or fixed version information changed.
    Before
    containernetworking/cni 0.8.1 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    After
    containernetworking/cni 0.8.1 · Fixed: For Windows Machine Config Operator upgrades, see the following documentation: https://docs.openshift.com/container-platform/latest/windows_containers/windows-node-upgrades.html
    Red Hat Product Security ↗
  2. Remediation statusRemediation status changed from Awaiting fix to Patch available.
    Before
    Awaiting fix
    After
    Patch available
    Red Hat Product Security ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release recorded from official guidance
ENISA EUVD · EUVD-2022-1255↗Red Hat Product Security security advisory↗CVE authority or vendor 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.
Free version - for non-commercial use only.CVE-2021-20206 · cve.blacktree.nl