DrupalCMS
CVE-2020-13664
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 · uneditedArbitrary PHP code execution vulnerability in Drupal Core under certain circumstances. An attacker could trick an administrator into visiting a malicious site that could result in creating a carefully named directory on the file system. With this directory in place, an attacker could attempt to brute force a remote code execution vulnerability. Windows servers are most likely to be affected. This issue affects: Drupal Drupal Core 8.8.x versions prior to 8.8.8; 8.9.x versions prior to 8.9.1; 9.0.1 versions prior to 9.0.1.
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 confidenceArbitrary PHP code execution vulnerability in Drupal Core where an attacker tricks an administrator into visiting a malicious site that creates a specially named directory on the file system; this directory then enables a brute force attack for remote code execution. Windows servers are most vulnerable.
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
DrupalCMS
>= 8.8.0, < 8.8.8>= 8.9.0, < 8.9.1>= 9.0.0, < 9.0.1CVSS 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
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/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 checksWork through these to decide whether this CVE applies to you.
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Check installed Drupal versionRun 'drush status' or view the 'Status report' page at /admin/reports/status, or check the VERSION file in the Drupal root directoryAffected if The version is >= 8.8.0 and < 8.8.8, OR >= 8.9.0 and < 8.9.1, OR >= 9.0.0 and < 9.0.1
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Identify the server operating systemRun 'uname' on Linux/Unix or 'systeminfo' on Windows, or check the server environment variablesAffected if The server is running Windows (this CVE affects Windows servers most severely)
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Inspect the Drupal file system for unexpected directoriesReview all directories in the Drupal root and sites/default/files directory for any newly created or unusually named directories that were not created by your organizationAffected if Any suspicious or specially named directories exist that were not intentionally created by administrators
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Check web server process file system permissionsReview the web server user permissions on the Drupal directory structure; verify that the web server process does not have write access to the Drupal root or module directories beyond what is intentionally permittedAffected if The web server process has overly broad write permissions to directories outside of the files directory
A user is affected if their Drupal version falls within the vulnerable ranges AND they are running on a Windows server with the described vulnerability conditions present.
Generated from the published advisory. Verify against your own configuration.
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 · scoped8.8.88.9.19.0.1
Update Drupal Core to version 8.8.8, 8.9.1, 9.0.1 or later. Until patched, restrict administrative access and monitor for unauthorized directory creation.
Drupal Core 8.8.8, 8.9.1, or 9.0.1 (depending on your current branch)
- 1. Back up your Drupal database and file system before making any changes
- 2. Identify your current Drupal version at admin/reports/status
- 3. Download the appropriate fixed version from www.drupal.org (8.8.8, 8.9.1, or 9.0.1 depending on your branch)
- 4. Put your site in maintenance mode at admin/config/development/maintenance
- 5. Replace the Drupal core files with the new version, preserving your configuration and sites directory
- 6. Run database updates by visiting update.php or using drush updatedb
- 7. Clear all Drupal caches using drush cr or admin/config/development/performance
- 8. Test the site functionality in a staging environment before deploying to production
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Drupal
Scoped from the published advisory
- Consultation2.0 h
- Implementation4.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,328.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-13664 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2020-13664 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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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.
- 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