CVE-2020-27304: Civetweb Project Civetweb

Critical severity, CVSS 9.8. EPSS: 3.2% chance of exploitation in the next 30 days.

The CivetWeb web library does not validate uploaded filepaths when running on an OS other than Windows, when using the built-in HTTP form-based file upload mechanism, via the mg_handle_form_request API. Web applications that use the file upload form handler, and use parts of the user-controlled filename in the output path, are susceptible to directory traversal

Affected products

• Civetweb Project Civetweb: from 1.8, before 1.15 (fixed in 1.15)
• Siemens Sinec Infrastructure Network Services: before 1.0.1.1 (fixed in 1.0.1.1)

Published 2021-10-21. Last modified 2026-06-17.