{"cve":"CVE-2020-27304","nvd":{"published":"2021-10-21T16:15:07.737","modified":"2026-06-17T03:09:08.483","status":"Modified","description":"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","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":9.8},"cwes":["CWE-22","CWE-23"],"references":["https://cert-portal.siemens.com/productcert/pdf/ssa-222547.pdf","https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf","https://groups.google.com/g/civetweb/c/yPBxNXdGgJQ","https://jfrog.com/blog/cve-2020-27304-rce-via-directory-traversal-in-civetweb-http-server/","https://cert-portal.siemens.com/productcert/pdf/ssa-222547.pdf"],"products":["civetweb_project:civetweb","siemens:sinec_infrastructure_network_services"],"source":"nvd","synced_at":"2026-10-19T21:24:39.218183596+00:00"},"epss":{"cve":"CVE-2020-27304","score":0.03241,"percentile":0.88299,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}