Evidence used
- No CISA KEV confirmation is currently recorded.
- EPSS is 0.63% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2023
CVE-2023-30539High confidence
Users can set up workflows using restricted and invisible system tags in Nextcloud
nextcloud · security-advisories
Official source article: GitHub GHSA-3M2F-V8X7-9W99 ↗. Check the applicable product and release in the original source.
6.5MediumCVSS 3.1
Scheduled
Patch availableMedium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityMedium→Operational priority:Medium, unchanged from published severity.unchanged
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
- Confirm that the asset runs nextcloud security-advisories and falls inside the recorded affected range.
- Verify the installed build against the product-specific fixed version after deployment.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.
Patch available01
What, why and how
Nextcloud is a personal home server system. Depending on the set up tags and other workflows this issue can be used to limit access of others or being able to grant them access when there are system tag based files access control or files retention rules. It is recommended that the Nextcloud Server is upgraded to 24.0.11 or 25.0.5, the Nextcloud Enterprise Server to 21.0.9.11, 22.2.10.11, 23.0.12.6, 24.0.11 or 25.0.5, and the Nextcloud Files automated tagging app to 1.11.1, 1.12.1, 1.13.1, 1.14.2, 1.15.3 or 1.16.1. Users unable to upgrade should disable all workflow related apps. Users are advised to upgrade.
What
Nextcloud is a personal home server system. Depending on the set up tags and other workflows this issue can be used to limit access of others or being able to grant them access when there are system tag based files access control or files retention rules. It is recommended that the Nextcloud Server is upgraded to 24.0.11 or 25.0.5, the Nextcloud Enterprise Server to 21.0.9.11, 22.2.10.11, 23.0.12.6, 24.0.11 or 25.0.5, and the Nextcloud Files automated tagging app to 1.11.1, 1.12.1, 1.13.1, 1.14.2, 1.15.3 or 1.16.1. Users unable to upgrade should disable all workflow related apps. Users are advised to upgrade.
Why
The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.
How
An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
What
Nextcloud is a personal home server system. Depending on the set up tags and other workflows this issue can be used to limit access of others or being able to grant them access when there are system tag based files access control or files retention rules. It is recommended that the Nextcloud Server is upgraded to 24.0.11 or 25.0.5, the Nextcloud Enterprise Server to 21.0.9.11, 22.2.10.11, 23.0.12.6, 24.0.11 or 25.0.5, and the Nextcloud Files automated tagging app to 1.11.1, 1.12.1, 1.13.1, 1.14.2, 1.15.3 or 1.16.1. Users unable to upgrade should disable all workflow related apps. Users are advised to upgrade.
Why
The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.
How
An attacker operating through a network path 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 No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.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 None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.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 Access Control → cause the confidentiality, integrity or availability impact described by the vendor
- Attack surface
- Network
- Privileges required
- Low: a basic authenticated account is required
- User interaction
- Required interaction required
- Attack complexity
- Low: no specialised conditions are recorded
- Security boundary
- Changed: exploitation can affect a different security authority
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-284 ↗
CWE-284: Improper Access Control. The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.
- 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:R/S:C/C:L/I:L/A:LCommon 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.UIRequiredUser interaction: Another user must perform an action for exploitation to succeed.SChangedScope: The attack can affect a component governed by a different security authority.CLowConfidentiality impact: A successful attack can cause a limited loss.ILowIntegrity impact: A successful attack can cause a limited loss.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.
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
- Nextcloud Server: < 24.0.11
- Nextcloud Server: >= 25.0.0, < 25.0.5
- Nextcloud Files automated tagging: >= 1.11.0, < 1.11.1
- Nextcloud Files automated tagging: >= 1.12.0, < 1.12.1
- Nextcloud Files automated tagging: >= 1.13.0, < 1.13.1
- Nextcloud Files automated tagging: >= 1.14.0, < 1.14.2
- Nextcloud Files automated tagging: >= 1.15.0, < 1.15.3
- Nextcloud Files automated tagging: >= 1.16.0, < 1.16.1
- Action
- Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
- 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 17 Apr 2023 · Last source change 5 Feb 2025, 20:38 UTC · CWE-284 · Improper Access Control
CVE recordCVE.org · 5.1
CVSS sourceCNA
EPSS source FIRST · tracked since 2026-08-14
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2023-34929
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
View recent updates ↗What changed after publication
No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.
CVE published
Fixed release or patch reference recorded
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.