IRONSMITHINTEL
HIGHCVSS8.8
|
Actively Exploited
|CISA KEV|CVE-2020-13671|Auth: low — authenticated user|Reboot: required|Manual only

Drupal core Un-restricted Upload of File

Improper sanitization in the extension file names is present in Drupal core.

Published Nov 20, 2020 · Updated May 16, 2026
Why patchRisk explained in plain English
Worst-case scenarioIf unpatched

A remote attacker, with a low-privilege account, can achieve full data confidentiality loss, arbitrary modification of data, complete denial of service or system unavailability. Federal agencies are required to remediate by 2022-07-18 under CISA BOD 22-01.

How the attack worksNo clicks needed

This is a Unrestricted File Upload (CWE-434) vulnerability in Drupal Drupal core. Drupal core does not properly sanitize certain filenames on uploaded files, which can lead to files being interpreted as the incorrect extension and served as the wrong MIME type or executed as PHP for certain hosting configurations. This issue affects: Drupal Drupal Core 9.0 versions prior to 9.0.8, 8.9 versions prior to 8.9.9, 8.8 versions prior to 8.8.11, and 7 versions prior to 7.74. Exploitation requires remote network access, low attack complexity, a low-privilege authenticated account, and no user interaction required.

Am I affected?Quick check

Probably yes if any of these apply:

IT Security
Running drupal: 7.0 ≤ v < 7.74, 8.8.0 ≤ v < 8.8.11, 8.9.0 ≤ v < 8.9.9, 9.0.0 ≤ v < 9.0.8; fedora: 32, 33
Real-world incidentsWhat we've seen

CISA added this CVE to the Known Exploited Vulnerabilities catalog on 2022-01-18 based on evidence of active exploitation in the wild. Federal agencies required to remediate by 2022-07-18.

How to patch

Manual remediation steps

Apply the Vendor Patch

This vulnerability is in the CISA Known Exploited Vulnerabilities catalog — apply the vendor's security update as soon as possible.

CISA required action: Apply updates per vendor instructions.

References

    1
    Vendor advisory: https://www.drupal.org/sa-core-2020-012
    1
    NVD entry: https://nvd.nist.gov/vuln/detail/CVE-2020-13671
    1
    CISA KEV: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-13671
PowerShell automationComing soon

No tested PowerShell script for this entry yet. We’re prioritising automation based on user demand.