CVE-2020-13664

Arbitrary 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.

Published: 2021-05-05 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2020-13664 is rated High Risk (66.1/100): CVSS High severity, with medium exploitation likelihood (EPSS 2.98%). Core evidence: EPSS rose +1.02% over the last day, indicating growing attacker interest. Mandatory action: High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2020-13664

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 1.96% 2.98% +1.02%
2 2025-12-28 1.32% 1.96% +0.64%
3 2025-12-27 1.32%

Full EPSS history (20 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-13664

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.8 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
2.8 5.9 [email protected]
9.3 2.0 HIGH
AV:N/AC:M/Au:N/C:C/I:C/A:C Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
8.6 10.0 [email protected]

Weakness enumeration for CVE-2020-13664

GitHub Security Advisory for CVE-2020-13664

GHSA-x72f-ggjw-v5xh · Severity: high · Ecosystem: composer — Drupal Core Arbitrary PHP code execution vulnerability

OS Trackers for CVE-2020-13664

vendor priority summary link
ubuntu medium CVE-2020-13664 medium priority: Ubuntu including 1 source packages (drupal7), 12 status rows across 12 suites (bionic, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, trusty, upstream, xenial): DNE 9, not-affected 3. https://ubuntu.com/security/CVE-2020-13664

Affected software / configurations for CVE-2020-13664

Vendor Product Version Raw CPE
drupal drupal >= 8.8.0, < 8.8.8 cpe:2.3:a:drupal:drupal:*:*:*:*:*:*:*:*
drupal drupal >= 8.9.0, < 8.9.1 cpe:2.3:a:drupal:drupal:*:*:*:*:*:*:*:*
drupal drupal >= 9.0.0, < 9.0.1 cpe:2.3:a:drupal:drupal:*:*:*:*:*:*:*:*

References for CVE-2020-13664

URL Tags
https://www.drupal.org/sa-core-2020-005 Vendor Advisory
cvelogic Threat Intelligence