CVE-2020-13671
Drupal 7.0 – 7.74
Raw vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2020-13671 is a high-severity Unrestricted Upload of File with Dangerous Type (CWE-434) vulnerability in Drupal Drupal. Its CVSS base score is 8.8 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Data Obfuscation (T1001); ranked in the top 2% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
Drupal core fails to properly sanitize certain filenames during file uploads, which can cause uploaded content to be interpreted under an incorrect extension. This leads to the file being served with the wrong MIME type or executed as PHP code under specific hosting configurations. The flaw affects Drupal Core versions 9.0 prior to 9.0.8, 8.9 prior to 8.9.9, 8.8 prior to 8.8.11, and 7 prior to 7.74, and is tracked under CWE-434.
An authenticated attacker with the ability to upload files can exploit the issue over the network with low complexity. Successful exploitation grants full control over confidentiality, integrity, and availability by allowing malicious files to be stored and later executed or served in an unintended manner, corresponding to the CVSS 8.8 rating.
The referenced Drupal security advisory SA-CORE-2020-012 and associated Fedora package announcements direct administrators to apply the fixed releases (7.74, 8.8.11, 8.9.9, or 9.0.8) as the primary mitigation. No public details on in-the-wild exploitation are provided in the source references.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2021-2168
Vulnerability Data
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:…
more
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.
- CWE(s)
- KEV Date Added
- 18 January 2022
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V5.1.1
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Requiring identifiable owners for portable devices reduces the attack surface for unrestricted uploads of dangerous file types via anonymous media.
Dangerous file uploads can be detonated in the chamber to determine malice before any production write or execution occurs.
Prevents unrestricted writing of arbitrary or malicious firmware by keeping hardware write-protect enabled except under tightly controlled manual procedures.
Scans files from external sources on download/open/execute, blocking unrestricted uploads of dangerous file types.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Hardened configuration baselines can enforce allowed file types and processing rules.
Restricting execution of unauthorized software directly blocks dangerous uploaded files from running.
Secure development practices include input validation and file-type restrictions that prevent this weakness.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.