{"cve":"CVE-2020-15233","nvd":{"published":"2020-10-02T21:15:12.403","modified":"2026-06-17T02:56:19.470","status":"Modified","description":"ORY Fosite is a security first OAuth2 & OpenID Connect framework for Go. In Fosite from version 0.30.2 and before version 0.34.1, there is an issue in which an an attacker can override the registered redirect URL by performing an OAuth flow and requesting a redirect URL that is to the loopback adapter. Attackers can provide both custom URL query parameters to their loopback redirect URL, as well as actually overriding the host of the registered redirect URL. These attacks are only applicable in scenarios where the attacker has access over the loopback interface. This vulnerability has been patched in ORY Fosite v0.34.1.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N","score":4.8},"cwes":["CWE-601","CWE-20"],"references":["https://github.com/ory/fosite/commit/cdee51ebe721bfc8acca0fd0b86b030ca70867bf","https://github.com/ory/fosite/security/advisories/GHSA-rfq3-w54c-f9q5","https://github.com/ory/fosite/commit/cdee51ebe721bfc8acca0fd0b86b030ca70867bf","https://github.com/ory/fosite/security/advisories/GHSA-rfq3-w54c-f9q5"],"products":["ory:fosite"],"source":"nvd","synced_at":"2026-10-19T21:09:53.489947993+00:00"},"epss":{"cve":"CVE-2020-15233","score":0.008,"percentile":0.56576,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-rfq3-w54c-f9q5","url":"https://osv.dev/vulnerability/GHSA-rfq3-w54c-f9q5","summary":"OAuth2 Redirect URL validity does not respect query parameters and character casing for loopback addresses","modified":"2026-07-08T05:59:55.707478334Z","packages":[{"ecosystem":"Go","name":"github.com/ory/fosite","purl":"pkg:golang/github.com/ory/fosite","ranges":[">=0.30.3 <0.34.1"],"fixed":["0.34.1"]}]}],"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."]}