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Full vulnerability report · 2021
CVE-2021-41089High confidence

`docker cp` allows unexpected chmod of host files

moby · moby

Official source article: GitHub GHSA-V994-F8VW-G7J4 ↗. Check the applicable product and release in the original source.

2.8LowCVSS 3.1
Recommended action
Patch only the product branches with a verified fix

Low technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority. Verified remediation exists for at least one product or source, but 1 structured product or package state remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Fix availability varies by product
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityLowOperational priority:Low, unchanged from published severity.unchanged

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • Exploitation requires an existing local or physical foothold with privileges.
  • EPSS is 0.29% for the current model date.

Compensating controls

  • Validate the affected product branch and deploy the verified fixed release.
  • Restrict local access and enforce least privilege on affected hosts.
  • Monitor vendor guidance and exploitation sources for a material change.

Verification

  1. Confirm that the asset runs moby moby 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: No default targetRemediation target: Normal maintenance

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.

Cross-source reconciliation

Remediation availability differs by product scope

Verified remediation exists for at least one product or source, but 1 structured product or package state remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Distribution package intelligence

Release-specific package status

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

7 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 · communitydockerVendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.20.10.9-r0Alpine Security Database ↗Source updated 11 Sep 2026
Alpine v3.22v3.22 · communitydockerVendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.20.10.9-r0Alpine Security Database ↗Source updated 11 Sep 2026
Alpine v3.21v3.21 · communitydockerVendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.20.10.9-r0Alpine Security Database ↗Source updated 19 Aug 2026
Debian trixietrixie · sourcedocker.ioVendor fix publishedDebian records a fixed source-package version for this release.20.10.10+dfsg1-1Debian Security Tracker ↗Source updated 6 Oct 2026
Debian bookwormbookworm · sourcedocker.ioVendor fix publishedDebian records a fixed source-package version for this release.20.10.10+dfsg1-1Debian Security Tracker ↗Source updated 6 Oct 2026
Debian forkyforky · sourcedocker.ioVendor fix publishedDebian records a fixed source-package version for this release.20.10.10+dfsg1-1Debian Security Tracker ↗Source updated 6 Oct 2026
Debian sidsid · sourcedocker.ioVendor fix publishedDebian records a fixed source-package version for this release.20.10.10+dfsg1-1Debian Security Tracker ↗Source updated 6 Oct 2026
Open-source package ranges1 source-attributed range

These OSV and GitHub advisory ranges apply only to the named package and ecosystem. A listed fixed version is not a universal product patch or proof that an update is installed.

Ecosystem and packageAffected rangeFirst fixed versionEvidence
Gogithub.com/docker/dockerSEMVER: introduced 0; fixed 20.10.920.10.9OSV record ↗aggregator derived · 10 Sep 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
SSA-222547 · CSAF 2.0 · revision 1 · finalSiemens ProductCERTSSA-222547: Third-Party Component Vulnerabilities in SCALANCE LPE9403 before V2.0
1 known affected

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

  • SCALANCE LPE9403
Summary
A vulnerability was found in Moby (Docker Engine) where attempting to copy files using docker cp into a specially-crafted container can result in Unix file permission changes for existing files in the host’s filesystem, widening access to others. This bug does not directly allow files to be read, modified, or executed without an additional cooperating process.
Remediation
Update to V2.0 or later version
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-2024-2176

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 actionPatch only the product branches with a verified fix

Low technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority. Verified remediation exists for at least one product or source, but 1 structured product or package state remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Fix availability varies by product
01

What, why and how

Moby is an open-source project created by Docker to enable software containerization. A bug was found in Moby (Docker Engine) where attempting to copy files using `docker cp` into a specially-crafted container can result in Unix file permission changes for existing files in the host’s filesystem, widening access to others. This bug does not directly allow files to be read, modified, or executed without an additional cooperating process. This bug has been fixed in Moby (Docker Engine) 20.10.9. Users should update to this version as soon as possible. Running containers do not need to be restarted.

What

Moby is an open-source project created by Docker to enable software containerization. A bug was found in Moby (Docker Engine) where attempting to copy files using `docker cp` into a specially-crafted container can result in Unix file permission changes for existing files in the host’s filesystem, widening access to others. This bug does not directly allow files to be read, modified, or executed without an additional cooperating process. This bug has been fixed in Moby (Docker Engine) 20.10.9. Users should update to this version as soon as possible. Running containers do not need to be restarted.

Why

The product does not preserve permissions or incorrectly preserves permissions when copying, restoring, or sharing objects, which can cause them to have less restrictive permissions than intended.

How

An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

Moby is an open-source project created by Docker to enable software containerization. A bug was found in Moby (Docker Engine) where attempting to copy files using `docker cp` into a specially-crafted container can result in Unix file permission changes for existing files in the host’s filesystem, widening access to others. This bug does not directly allow files to be read, modified, or executed without an additional cooperating process. This bug has been fixed in Moby (Docker Engine) 20.10.9. Users should update to this version as soon as possible. Running containers do not need to be restarted.

Why

The product does not preserve permissions or incorrectly preserves permissions when copying, restoring, or sharing objects, which can cause them to have less restrictive permissions than intended.

How

An attacker operating through local access may attempt exploitation with low 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
local access → Improper Preservation of Permissions → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Local
Privileges required
Low: a basic authenticated account is required
User interaction
None
Attack complexity
High: exploitation depends on specific conditions
Security boundary
Changed: exploitation can affect a different security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-281 ↗

CWE-281: Improper Preservation of Permissions. The product does not preserve permissions or incorrectly preserves permissions when copying, restoring, or sharing objects, which can cause them to have less restrictive permissions than intended.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:L/I:N/A:N

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVLocalAttack vector: The attacker needs local access to the vulnerable system.ACHighAttack complexity: Successful exploitation depends on specific conditions outside the attacker's direct control.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.SChangedScope: The attack can affect a component governed by a different security authority.CLowConfidentiality impact: A successful attack can cause a limited loss.INoneIntegrity impact: No direct loss is represented by this metric.ANoneAvailability impact: No direct loss is represented by this metric.
Post-exploitation / living off the land
The issue can support a local privilege or sandbox boundary transition; normal system utilities may then be available in the gained context.
CWE-281
A

Official authority intelligence

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

BSI · German · WID-SEC-2022-1738IBM InfoSphere Information Server: Mehrere Schwachstellen

Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in IBM InfoSphere Information Server ausnutzen, um seine Privilegien zu erweitern, beliebigen Programmcode auszuführen, einen Cross-Site-Scripting-Angriff durchzuführen, Informationen offenzulegen, einen Denial of Service Zustand herbeizuführen, Dateien zu manipulieren oder Sicherheitsvorkehrungen zu umgehen.

Official advisory ↗
BSI · German · WID-SEC-2023-1124docker: Mehrere Schwachstellen

Ein lokaler Angreifer kann mehrere Schwachstellen in docker ausnutzen, um seine Privilegien zu erhöhen oder Informationen offenzulegen.

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20211006Security Bulletin 06 Oct 2021

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 06 Oct 2021, published on 6 October 2021. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0199Multiples vulnérabilités dans les produits VMware

/CVERecord?id=CVE-2021-3449 Référence CVE CVE-2021-3711 https://www.cve.org/CVERecord?id=CVE-2021-3711 Référence CVE CVE-2021-3712 https://www.cve.org/CVERecord?id=CVE-2021-3712 Référence CVE CVE-2021-37600 https://www.cve.org/CVERecord?id=CVE-2021-37600 Référence CVE CVE-2021-38297 https://www.cve.org/CVERecord?id=CVE-2021-38297 Référence CVE CVE-2021-38561 https://www.cve.org/CVERecord?id=CVE-2021-38561 Référence CVE CVE-2021-39293 https://www.cve.org/CVERecord?id=CVE-2021-39293 Référence CVE CVE-2021-3995 https://www.cve.org/CVERecord?id=CVE-2021-3995 Référence CVE CVE-2021-3996 https://www.cve.org/CVERecord?id=CVE-2021-3996 Référence CVE CVE-2021-41089 https://www.cve.org/CVERecord?id=CVE-2021-41089 Référence CVE CVE-2021-41091 https://www.cve.org/CVERecord?id=CVE-2021-41091 Référence CVE CVE-2021-4160 https://www.cve.org/CVERecord?id=CVE-2021-4160 Référence CVE CVE-2021-41771 https://www.cve.org/CVERecord?id=CVE-2021-41771 Référence CVE CVE-2021-41772 https://www.cve.org/CVERecord?id=CVE-2021-41772 Référence CVE CVE-2021-42374 https://www.cve.org/CVERecord?id=CVE-2021-42374 Référence CVE CVE-2021-42376 https://www.cve.org/CVERecord?id=CVE-2021-42376 Référence CVE CVE-2021-42378 https://www.cve.org/CVERecord?id=CVE-2021-42378 Référence CVE CVE-2021-42379 https://www.cve.org/CVERecord?id=CV

Official advisory ↗
CERT-FR · French · CERTFR-2022-AVI-547Multiples vulnérabilités dans les produits Siemens

ord?id=CVE-2021-33910 Référence CVE CVE-2021-34798 https://www.cve.org/CVERecord?id=CVE-2021-34798 Référence CVE CVE-2021-36221 https://www.cve.org/CVERecord?id=CVE-2021-36221 Référence CVE CVE-2021-37182 https://www.cve.org/CVERecord?id=CVE-2021-37182 Référence CVE CVE-2021-37209 https://www.cve.org/CVERecord?id=CVE-2021-37209 Référence CVE CVE-2021-39275 https://www.cve.org/CVERecord?id=CVE-2021-39275 Référence CVE CVE-2021-39293 https://www.cve.org/CVERecord?id=CVE-2021-39293 Référence CVE CVE-2021-4034 https://www.cve.org/CVERecord?id=CVE-2021-4034 Référence CVE CVE-2021-40438 https://www.cve.org/CVERecord?id=CVE-2021-40438 Référence CVE CVE-2021-41089 https://www.cve.org/CVERecord?id=CVE-2021-41089 Référence CVE CVE-2021-41091 https://www.cve.org/CVERecord?id=CVE-2021-41091 Référence CVE CVE-2021-41092 https://www.cve.org/CVERecord?id=CVE-2021-41092 Référence CVE CVE-2021-41103 https://www.cve.org/CVERecord?id=CVE-2021-41103 Référence CVE CVE-2021-45960 https://www.cve.org/CVERecord?id=CVE-2021-45960 Référence CVE CVE-2021-46143 https://www.cve.org/CVERecord?id=CVE-2021-46143 Référence CVE CVE-2022-0778 https://www.cve.org/CVERecord?id=CVE-2022-0778 Référence CVE CVE-2022-0847 https://www.cve.org/CVERecord?id=CVE-2022-0847 Référence CVE CVE-2022-22822 https://www.cve.org/CVERecord?id=CVE-

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2021-012553Moby におけるパーミッションの不適切な保持に関する脆弱性

Moby (Docker Engine) には、パーミッションの不適切な保持に関する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.
Fix availability varies by product
Affected
SCALANCE LPE9403
Fixed
An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
Action
Use the product-specific evidence above. Patch only products with a verified fixed release, and keep every affected or under-investigation state without a matching fix in the remediation queue.
Workaround
No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
04

Evidence and provenance

Published 4 Oct 2021 · Last source change 4 Aug 2024, 02:59 UTC · CWE-281 · Improper Preservation of Permissions

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-2024-2176
Product sourceVendor CSAF · Siemens ProductCERT
Remediation sourceVendor CSAF · Siemens ProductCERT
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.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
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-2021-41089 · cve.blacktree.nl