{"cve":"CVE-2021-36191","nvd":{"published":"2021-12-08T13:15:07.787","modified":"2026-06-17T03:58:29.837","status":"Modified","description":"A url redirection to untrusted site ('open redirect') in Fortinet FortiWeb version 6.4.1 and below, 6.3.15 and below allows attacker to use the device as proxy via crafted GET parameters in requests to error handlers","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N","score":5.4},"cwes":["CWE-601"],"references":["https://fortiguard.com/advisory/FG-IR-21-133","https://fortiguard.com/advisory/FG-IR-21-133"],"products":["fortinet:fortiweb"],"source":"nvd","synced_at":"2026-10-19T21:25:41.256909649+00:00"},"epss":{"cve":"CVE-2021-36191","score":0.00523,"percentile":0.444,"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."]}