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Full vulnerability report · 2023
CVE-2023-20900High confidence

n/a VMware Tools — Authentication Bypass by Capture-replay

Unknown · VMware Tools

7.1HighCVSS 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 1.46% 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 Unknown VMware Tools 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 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 · communityopen-vm-toolsVendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.12.3.0-r0Alpine Security Database ↗Source updated 11 Sep 2026
Alpine v3.22v3.22 · communityopen-vm-toolsVendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.12.3.0-r0Alpine Security Database ↗Source updated 11 Sep 2026
Alpine v3.21v3.21 · communityopen-vm-toolsVendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.12.3.0-r0Alpine Security Database ↗Source updated 19 Aug 2026
Debian trixietrixie · sourceopen-vm-toolsVendor fix publishedDebian records a fixed source-package version for this release.2:12.3.0-1Debian Security Tracker ↗Source updated 5 Oct 2026
Debian bookwormbookworm · sourceopen-vm-toolsVendor fix publishedDebian records a fixed source-package version for this release.2:12.2.0-1+deb12u1Debian Security Tracker ↗Source updated 5 Oct 2026
Debian forkyforky · sourceopen-vm-toolsVendor fix publishedDebian records a fixed source-package version for this release.2:12.3.0-1Debian Security Tracker ↗Source updated 5 Oct 2026
Debian sidsid · sourceopen-vm-toolsVendor fix publishedDebian records a fixed source-package version for this release.2:12.3.0-1Debian Security Tracker ↗Source updated 5 Oct 2026
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-2023-25069

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

A malicious actor that has been granted Guest Operation Privileges https://docs.vmware.com/en/VMware-vSphere/8.0/vsphere-security/GUID-6A952214-0E5E-4CCF-9D2A-90948FF643EC.html  in a target virtual machine may be able to elevate their privileges if that target virtual machine has been assigned a more privileged Guest Alias https://vdc-download.vmware.com/vmwb-repository/dcr-public/d1902b0e-d479-46bf-8ac9-cee0e31e8ec0/07ce8dbd-db48-4261-9b8f-c6d3ad8ba472/vim.vm.guest.AliasManager.html .

What

A malicious actor that has been granted Guest Operation Privileges https://docs.vmware.com/en/VMware-vSphere/8.0/vsphere-security/GUID-6A952214-0E5E-4CCF-9D2A-90948FF643EC.html  in a target virtual machine may be able to elevate their privileges if that target virtual machine has been assigned a more privileged Guest Alias https://vdc-download.vmware.com/vmwb-repository/dcr-public/d1902b0e-d479-46bf-8ac9-cee0e31e8ec0/07ce8dbd-db48-4261-9b8f-c6d3ad8ba472/vim.vm.guest.AliasManager.html .

Why

A capture-replay flaw exists when the design of the product makes it possible for a malicious user to sniff network traffic and bypass authentication by replaying it to the server in question to the same effect as the original message (or with minor changes).

How

An attacker operating through an adjacent network may attempt exploitation with low privileges. If successful, the issue may gain additional privileges.

What

A malicious actor that has been granted Guest Operation Privileges https://docs.vmware.com/en/VMware-vSphere/8.0/vsphere-security/GUID-6A952214-0E5E-4CCF-9D2A-90948FF643EC.html  in a target virtual machine may be able to elevate their privileges if that target virtual machine has been assigned a more privileged Guest Alias https://vdc-download.vmware.com/vmwb-repository/dcr-public/d1902b0e-d479-46bf-8ac9-cee0e31e8ec0/07ce8dbd-db48-4261-9b8f-c6d3ad8ba472/vim.vm.guest.AliasManager.html .

Why

A capture-replay flaw exists when the design of the product makes it possible for a malicious user to sniff network traffic and bypass authentication by replaying it to the server in question to the same effect as the original message (or with minor changes).

How

An attacker operating through an adjacent network may attempt exploitation with low privileges. If successful, the issue may gain additional privileges.

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
an adjacent network → Authentication Bypass by Capture-replay → gain additional privileges
Attack surface
Adjacent
Privileges required
Low: a basic authenticated account is required
User interaction
None
Attack complexity
High: exploitation depends on specific conditions
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-294 ↗

CWE-294: Authentication Bypass by Capture-replay. A capture-replay flaw exists when the design of the product makes it possible for a malicious user to sniff network traffic and bypass authentication by replaying it to the server in question to the same effect as the original message (or with minor changes).

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

AVAdjacentAttack vector: The attacker must be on an adjacent or logically close network.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.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.
Privilege escalationCWE-294
A

Official authority intelligence

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

BSI · German · WID-SEC-2023-2902IBM Security Guardium: Mehrere Schwachstellen

Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in IBM Security Guardium ausnutzen, um seine Privilegien zu erweitern, beliebigen Programmcode auszuführen, Sicherheitsvorkehrungen zu umgehen, Dateien zu manipulieren, einen Denial of Service Zustand herbeizuführen oder Informationen offenzulegen.

Official advisory ↗
BSI · German · WID-SEC-2023-2241VMware Tools: Schwachstelle ermöglicht Umgehen von Sicherheitsvorkehrungen

Ein entfernter, anonymer Angreifer kann eine Schwachstelle in VMware Tools ausnutzen, um Sicherheitsvorkehrungen zu umgehen.

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20230906Security Bulletin 06 Sep 2023

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 06 Sep 2023, published on 6 September 2023. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2024-AVI-0947Vulnérabilité dans NetApp ONTAP Select Deploy administration utility

Une vulnérabilité a été découverte dans NetApp ONTAP Select Deploy administration utility. Elle permet à un attaquant de provoquer un déni de service à distance, une atteinte à la confidentialité des données et une atteinte à l'intégrité des données.

Official advisory ↗
CERT-FR · French · CERTFR-2023-AVI-0958Multiples vulnérabilités dans IBM

De multiples vulnérabilités ont été découvertes dans les produits IBM . Certaines d'entre elles permettent à un attaquant de provoquer une élévation de privilèges, une atteinte à la confidentialité des données et une exécution de code arbitraire à distance.

Official advisory ↗
CERT-FR · French · CERTFR-2023-AVI-0950Multiples vulnérabilités dans Juniper Secure Analytics

De multiples vulnérabilités ont été découvertes dans Juniper Secure Analytics . Certaines d'entre elles permettent à un attaquant de provoquer une exécution de code arbitraire à distance, un déni de service à distance et un contournement de la politique de sécurité.

Official advisory ↗
CERT-FR · French · CERTFR-2023-AVI-0702Vulnérabilité dans VMware Tools

Une vulnérabilité a été découverte dans VMware Tools. Elle permet à un attaquant de provoquer un contournement de la politique de sécurité.

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2023-011844VMware の VMware Tools および open-vm-tools における Capture-replay による認証回避に関する脆弱性

VMware の VMware Tools および open-vm-tools には、Capture-replay による認証回避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.
Patch available
Affected
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
Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
Workaround
No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
04

Evidence and provenance

Published 31 Aug 2023 · Last source change 2 Aug 2024, 09:21 UTC · CWE-294 · Authentication Bypass by Capture-replay

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-2023-25069
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceNIST NVD
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 ↗

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-2023-20900 · cve.blacktree.nl