How severe is CVE-2020-13671?

CVE-2020-13671 has a CVSS score of 8.8/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2020-13671?

CVE-2020-13671 affects the following packages: drupal/core (Packagist), drupal/core (Packagist), drupal/core (Packagist), drupal/core (Packagist), drupal/drupal (Packagist), drupal/drupal (Packagist), drupal/drupal (Packagist), drupal/drupal (Packagist). Ecosystems affected: Packagist.

How do I fix CVE-2020-13671?

Update drupal/core to 9.0.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-13671 is resolved across your whole dependency graph.

How do I detect CVE-2020-13671 in my Packagist dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for drupal/core. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2020-13671 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2020-13671?

O3 pinpoints whether CVE-2020-13671 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2020-13671 actively exploited in the wild?

Yes. There are 2 known exploit references for CVE-2020-13671, including 2 in-the-wild exploitations observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2020-13671?

CVE-2020-13671 has an EPSS (Exploit Prediction Scoring System) score of 4.3%, placing it in the 90th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

Is CVE-2020-13671 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2020-13671 (Drupal core Un-restricted Upload of File) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2022-01-18. CISA required all US federal civilian agencies to remediate this vulnerability by 2022-07-18. The required action was: Apply updates per vendor instructions. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

What type of vulnerability is CVE-2020-13671?

CVE-2020-13671 is classified as Unrestricted File Upload (CWE-434). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2020-13671 published, and has it been updated?

CVE-2020-13671 was published on November 20, 2020 and was last updated on July 8, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CISA KEV·Added 2022-01-18 — agencies required to remediate by 2022-07-18

🐘 Packagist

CVE-2020-13671

HIGH

Drupal core Unrestricted Upload of File with Dangerous Type

Also known asBIT-drupal-2020-13671DRUPAL-CORE-2020-012GHSA-68jc-v27h-vhmw

Published

Nov 20, 2020

Updated

Jul 8, 2026

Affected

8 pkgs

Patched

8 / 8

Exploits

2 known

EPSS Exploitation Probability

via FIRST.org ↗

4.3%probability of exploitation in next 30 days

Lower Risk90th percentile+0.04%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

8 pkgs affected

🐘drupal/core🐘drupal/core🐘drupal/core🐘drupal/core🐘drupal/drupal🐘drupal/drupal🐘drupal/drupal🐘drupal/drupal

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.

Description

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.

Affected Packages

8 total 8 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`drupal/core`	≥ 9.0.0&&< 9.0.8	9.0.8
🐘Packagist	`drupal/core`	≥ 8.9.0&&< 8.9.9	8.9.9
🐘Packagist	`drupal/core`	≥ 8.0.0&&< 8.8.11	8.8.11
🐘Packagist	`drupal/core`	≥ 7.0.0&&< 7.74	7.74
🐘Packagist	`drupal/drupal`	≥ 7.0.0&&< 7.74	7.74
🐘Packagist	`drupal/drupal`	≥ 8.0.0&&< 8.8.11	8.8.11

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

Drupal core does not properly sanitize certain filenames on uploaded fil…

unit42.paloaltonetworks.comAPIApr 2021

Drupal core does not properly sanitize certain filenames on uploaded fil…

cisa.govCISAJan 2022

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for drupal/core. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update drupal/core to 9.0.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-13671 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2020-13671 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2020-13671. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2020-13671 in your dependencies?

O3 detects CVE-2020-13671 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works