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Full vulnerability report · 2025
CVE-2025-21173High confidence

.NET Elevation of Privilege Vulnerability

Microsoft · .NET 8.0

7.3HighCVSS 3.1
Recommended action
Within 7 days

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

Fix not verified
Distribution package intelligence

Ubuntu vendor package status

Canonical’s release and source-package findings are shown separately from local repository availability.

1 package state
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.

Ubuntu releaseSource packageVendor stateFixed versionEvidence
Ubuntu 24.04 LTSnoble · standard archivedotnet8Vendor fix publishedCanonical reports that a fixed source package version has been published. Repository candidate availability is not checked by BlackTree.8.0.112-8.0.12-0ubuntu1~24.04.1Canonical record ↗Source updated 9 Sept 2026
Optional official sources

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

Select the national-authority views to include. The exact source language is shown on each matched advisory. Your choice is remembered on this device and encoded in the shareable URL.

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-2025-2256

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.

Fix not verified
01

What, why and how

.NET Elevation of Privilege Vulnerability

What

.NET Elevation of Privilege Vulnerability

Why

The product creates a temporary file in a directory whose permissions allow unintended actors to determine the file's existence or otherwise access that file.

How

An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may gain additional privileges.

What

.NET Elevation of Privilege Vulnerability

Why

The product creates a temporary file in a directory whose permissions allow unintended actors to determine the file's existence or otherwise access that file.

How

An attacker operating through local access 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
local access → Creation of Temporary File in Directory with Insecure Permissions → gain additional privileges
Attack surface
Local
Privileges required
Low: a basic authenticated account is required
User interaction
Required interaction required
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-379 ↗

CWE-379: Creation of Temporary File in Directory with Insecure Permissions. The product creates a temporary file in a directory whose permissions allow unintended actors to determine the file's existence or otherwise access that file.

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:L/PR:L/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

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.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.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
The issue can support a local privilege or sandbox boundary transition; normal system utilities may then be available in the gained context.
Privilege escalationCWE-379
A

Official authority intelligence

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

BSI · German · WID-SEC-W-2025-0093Microsoft Developer Tools: Mehrere Schwachstellen

Ein Angreifer kann mehrere Schwachstellen in Microsoft Visual Studio 2017, Microsoft .NET Framework, Microsoft Windows Server 2012, Microsoft Windows Server 2012 R2, Microsoft Windows Server 2016, Microsoft Windows Server 2019, Microsoft Windows Server 2022, Microsoft Visual Studio 2019, Microsoft Visual Studio 2022 und Microsoft Windows ausnutzen, um seine Privilegien zu erhöhen, beliebigen Code auszuführen und vertrauliche Informationen preiszugeben.

Official advisory
CERT-FR · French · CERTFR-2025-AVI-0040Multiples vulnérabilités dans Microsoft .Net

De multiples vulnérabilités ont été découvertes dans Microsoft .Net. Elles permettent à un attaquant de provoquer une exécution de code arbitraire à distance et une élévation de privilèges.

Official advisory
CERT-FR · French · CERTFR-2025-AVI-0041Multiples vulnérabilités dans les produits Microsoft

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

Official advisory
NCSC-NL · Dutch · NCSC-2025-0011Kwetsbaarheden verholpen in Microsoft Developer Tools

Een kwaadwillende kan de kwetsbaarheden misbruiken om zich verhoogde rechten toe te kennen, toegang te krijgen tot gevoelige gegevens of om willekeurige code uit te voeren in de context van het slachtoffer. Voor succesvol misbruik moet de kwaadwillende het slachtoffer misleiden een malafide bestand te openen en verwerken. ``` Visual Studio: |----------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |----------------|------|-------------------------------------| | CVE-2024-50338 | 7.40 | Toegang tot gevoelige gegevens | | CVE-2025-21178 | 8.80 | Uitvoeren van willekeurige code | | CVE-2025-21405 | 7.30 | Verkrijgen van verhoogde rechten | |----------------|------|-------------------------------------| .NET, .NET Framework, Visual Studio: |----------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |----------------|------|-------------------------------------| | CVE-2025-21176 | 8.80 | Uitvoeren van willekeurige code | |----------------|------|-------------------------------------| .NET: |----------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |----------------|------|-------------------------------------| | CVE-2025-21171 | 8.10 | Uitvoeren van willekeurige code | | CVE-2025-21173 | 8.00 | Verkrijgen van verhoogde rechten | |----------------|------|-------------------------------------| .NET and Visual Studio: |----------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |----------------|------|-------------------------------------| | CVE-2025-21172 | 7.50 | Uitvoeren van willekeurige code | |----------------|------|-------------------------------------| ```

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 not verified
Affected
8.0.0 < 8.0.12; 9.0.0 < 9.0.1; 17.10.0 < 17.10.10; 17.12.0 < 17.12.4; 17.6.0 < 17.6.22; 17.8.0 < 17.8.17
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. Limit untrusted access and use least privilege until authoritative guidance is available.
04

Evidence and provenance

Published 14 Jan 2025 · Last source change 9 Jun 2026, 18:29 UTC · CWE-379 · Creation of Temporary File in Directory with Insecure Permissions

CVE recordCVE.org · 5.2
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-2025-2256
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceOther authority
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
CVE published
ENISA EUVD · EUVD-2025-2256↗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-2025-21173 · cve.blacktree.nl