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File FirewallApplication · Owncloud

CVE-2020-36249

HIGH · 7.5 CVSS v3.1 Published 2021-02-19
Fix available
A fix is available. Upgrade to 2.8.0 or later.
See remediation →
84/100
Remediation priority · High
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
The File Firewall before 2.8.0 for ownCloud Server does not properly enforce file-type restrictions for public shares.

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 · moderate confidence

The File Firewall app for ownCloud Server versions before 2.8.0 fails to properly enforce file-type restrictions when files are accessed via public share links. This allows users to bypass configured file-type blocking rules when accessing files through public links, potentially exposing the system to prohibited file types.

MitigationUpgrade the File Firewall app to version 2.8.0 or later. Review existing firewall rules to confirm file-type restrictions are properly configured for public shares.

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
File FirewallApplication
Affected:< 2.8.0

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

CVSS:3.1/AV:N/AC:L/PR:N/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 File Firewall app installation and version
    Use the ownCloud command-line interface (occ) to list installed apps and retrieve the File Firewall app version, or check through the ownCloud admin marketplace interface
    Affected if The File Firewall app is installed with a version lower than 2.8.0
  2. Review file-type blocking rules
    Access the File Firewall configuration panel in ownCloud admin settings and list all configured rules that block specific file types
    Affected if File-type blocking rules exist and are configured in the firewall
  3. Verify rule scope includes public shares
    Examine each file-type blocking rule to determine whether the rule applies to public share link access, checking the rule scope or user group assignment settings
    Affected if The configured file-type blocking rules do NOT explicitly include public share link access as an applicable context or condition

The environment is affected if the File Firewall app version is below 2.8.0 AND file-type blocking rules exist but do not cover public share link access, allowing the bypass condition to exist.

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.

From vendor data
Upgrade available Upgrade to 2.8.0 or later
Fixed in 2.8.0
Interim mitigation

Upgrade the File Firewall app to version 2.8.0 or later. Review existing firewall rules to confirm file-type restrictions are properly configured for public shares.

Fix this in File Firewall Scoped from the published advisory
  • Consultation1.0 h
  • Implementation1.0 h
  • Testing2.0 h
  • Review / QA1.0 h
5.0 hours of engineering $860
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,376.

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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-2020-36249 in production — separate from our analysis above.

No notes yet

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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