CVE-2020-13671
Drupal core Un-restricted Upload of File
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 status
CISA Known Exploited Vulnerabilities
Listed by CISA on 18 January 2022. US federal agencies were required to remediate it by 18 July 2022.
EPSS — exploitation probability
FIRST puts the probability of exploitation activity in the next 30 days at 35.4%, which is higher than 98.4% of all scored vulnerabilities. EPSS is a forecast of activity, not a measure of severity, and it is rescored daily.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Frequently asked questions
Is CVE-2020-13671 being exploited by ransomware groups?
No ransomware group in this database is currently recorded as exploiting CVE-2020-13671.
What does CVE-2020-13671 affect?
CVE-2020-13671 affects 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.
How severe is CVE-2020-13671?
CVE-2020-13671 is rated HIGH with a CVSS base score of 8.8. EPSS puts the probability of exploitation in the next 30 days at 35.4%, higher than 98.4% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 18 July 2022.
How should organisations respond to CVE-2020-13671?
Apply the vendor patch for Drupal core as the first priority, and treat any internet-facing instance as the most urgent. Because this vulnerability is associated with ransomware activity, also review whether the affected systems were reachable before patching, rather than assuming that patching alone closes the incident.