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Owncloud ServerApplication · Owncloud

CVE-2023-49105

CRITICAL · 9.8 CVSS v3.1 Published 2023-11-21
Fix available
A fix is available. Upgrade to 10.13.1 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges 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
An issue was discovered in ownCloud owncloud/core before 10.13.1. An attacker can access, modify, or delete any file without authentication if the username of a victim is known, and the victim has no signing-key configured. This occurs because pre-signed URLs can be accepted even when no signing-key is configured for the owner of the files. The earliest affected version is 10.6.0.

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

In ownCloud core before 10.13.1, pre-signed URL validation fails when the file owner has not configured a signing-key. Attackers who know a victim's username can craft pre-signed URLs that bypass authentication entirely, allowing unauthorized access, modification, or deletion of any files belonging to that user.

MitigationUpgrade ownCloud/core to version 10.13.1 or later. As a workaround, ensure all users have signing-keys configured to enforce proper pre-signed URL validation.

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
Owncloud ServerApplication
Affected:>= 10.6.0, < 10.13.1

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
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

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. Check ownCloud version
    Locate the installed ownCloud version (typically visible in the admin dashboard or in a version file such as version.php in the ownCloud root directory). Compare this version number against the affected range: 10.6.0 through 10.13.0.
    Affected if Installed version is 10.6.0 or higher but lower than 10.13.1
  2. Identify users without signing keys
    Query the ownCloud database or user backend to determine which users have a signing key configured. Look for a signing key or secret field associated with user accounts.
    Affected if Any user account (particularly potential targets) lacks a configured signing key in the system
  3. Verify pre-signed URL generation
    Attempt to generate a pre-signed URL for a file owned by a user known to lack a signing key, or inspect the ownCloud signing configuration to confirm whether enforcement of signing keys is active.
    Affected if Pre-signed URLs can be generated for users without signing keys, indicating validation is not enforced
  4. Confirm authentication bypass
    Using a known username without a signing key, craft a pre-signed URL for that user's files and attempt to access it from an unauthenticated context.
    Affected if The URL grants access without requiring valid authentication, confirming the bypass is exploitable

User is affected if ownCloud version is 10.6.0 or higher but lower than 10.13.1 AND at least one user account (especially the victim) does not have a signing key configured, allowing pre-signed URLs to bypass authentication.

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 10.13.1 or later
Fixed in 10.13.1
Interim mitigation

Upgrade ownCloud/core to version 10.13.1 or later. As a workaround, ensure all users have signing-keys configured to enforce proper pre-signed URL validation.

Recommended fix High confidence

ownCloud Server 10.13.1

  1. 1. Create a complete backup of the ownCloud Server database, config directory, and data directory
  2. 2. Download ownCloud Server version 10.13.1 from the official ownCloud download page
  3. 3. Stop the ownCloud web server service (e.g., Apache or Nginx)
  4. 4. Replace the existing ownCloud files with the new version 10.13.1 files, preserving the config directory
  5. 5. Start the web server service
  6. 6. Verify the upgrade was successful by logging into the ownCloud web interface
  7. 7. Confirm the vulnerability is patched by ensuring pre-signed URLs require a valid signing-key when the owner has no signing-key configured
Caveat Review ownCloud 10.13 release notes for any breaking changes between your current version and 10.13.1, particularly regarding deprecated features or database migrations

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

Fix this in Owncloud Server Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,860
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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-2023-49105 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