Umbraco CmsApplication · Umbraco

CVE-2023-49089

MEDIUM · 6.5 CVSS v3.1 Published 2023-12-12
Fix available
A fix is available. Upgrade to 8.18.10 / 10.8.1 or later.
See remediation →
71/100
Remediation priority · Elevated
Remotely reachable Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Umbraco is an ASP.NET content management system (CMS). Starting in version 8.0.0 and prior to versions 8.18.10, 10.8.1, and 12.3.0, Backoffice users with permissions to create packages can use path traversal and thereby write outside of the expected location. Versions 8.18.10, 10.8.1, and 12.3.0 contain a patch for this issue.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Path traversal vulnerability in Umbraco CMS allows authenticated backoffice users with package creation permissions to write files outside the intended directory by manipulating file paths during package creation. This is a directory traversal issue in the package creation feature.

MitigationUpgrade to Umbraco versions 8.18.10, 10.8.1, or 12.3.0 (or later). Until patching is possible, restrict package creation permissions to only highly trusted administrators.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Umbraco CmsApplication
Affected:>= 8.0.0, < 8.18.10>= 10.0.0, < 10.8.1>= 12.0.0, < 12.3.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify the installed Umbraco version
    Check the version from the web.config file, the ~/bin/Umbraco.Core.dll file properties, or log into the backoffice and navigate to the About/Version section in the Help drawer
    Affected if The installed version is 8.0.0 through 8.18.9, 10.0.0 through 10.8.0, or 12.0.0 through 12.2.0 (any version less than 8.18.10, 10.8.1, or 12.3.0 respectively)
  2. Verify if package creation permissions exist
    In the Umbraco backoffice, go to the Users section and review the roles or groups assigned to each user. Check if any role includes the 'Packages' or 'Create Package' permission under the Access permissions
    Affected if Any user account has been granted package creation or package management permissions in the backoffice
  3. Review recent package creation activity
    Check the ~/App_Data/Packages/ directory for any package zip files. Also review server file logs and the Umbraco audit log (if enabled) for package creation events around the time of suspected exploitation
    Affected if Any unexpected package files exist outside the intended ~/App_Data/Packages/ directory, or if package creation activity was performed by an untrusted user
  4. Inspect web server write locations
    Use file system auditing or review the web server logs to identify any file write operations to directories outside the expected Umbraco application folders (such as the root web directory or system directories) that coincide with package creation feature usage
    Affected if Files were written to directories outside the intended App_Data/Packages/ path after package creation feature was used

You are affected if your Umbraco installation version is below 8.18.10, 10.8.1, or 12.3.0 AND any backoffice user has package creation permissions, regardless of whether exploitation has occurred.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 8.18.10 / 10.8.1 / 12.3.0 or later
Fixed in 8.18.1010.8.112.3.0
Interim mitigation

Upgrade to Umbraco versions 8.18.10, 10.8.1, or 12.3.0 (or later). Until patching is possible, restrict package creation permissions to only highly trusted administrators.

Recommended fix High confidence

Umbraco CMS 8.18.10 (for 8.x), 10.8.1 (for 10.x), or 12.3.0 (for 12.x)

  1. Backup your Umbraco database and application files before proceeding with any upgrade
  2. Identify your current Umbraco version by checking the /Properties/AssemblyInfo.cs or your project references
  3. For Umbraco 8.x installations: Upgrade to version 8.18.10 or later by updating the UmbracoCms package reference in your .csproj file
  4. For Umbraco 10.x installations: Upgrade to version 10.8.1 or later by updating the UmbracoCms package reference in your .csproj file
  5. For Umbraco 12.x installations: Upgrade to version 12.3.0 or later by updating the UmbracoCms package reference in your .csproj file
  6. Run dotnet restore to fetch the new package versions
  7. Rebuild and test your solution locally before deploying to production
  8. Deploy the updated application to your environment
Caveat Review Umbraco release notes for breaking changes between your current version and the target upgrade version before upgrading

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Umbraco Cms Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing5.0 h
  • Review / QA2.0 h
16.0 hours of engineering $2,790
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Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2023-49089 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data