{"cve":"CVE-2021-20789","nvd":{"published":"2021-07-30T14:15:14.893","modified":"2026-06-17T03:34:27.370","status":"Modified","description":"Open redirect vulnerability in GroupSession (GroupSession Free edition from ver2.2.0 to the version prior to ver5.1.0, GroupSession byCloud from ver3.0.3 to the version prior to ver5.1.0, and GroupSession ZION from ver3.0.3 to the version prior to ver5.1.0) allows a remote attacker to redirect a user to an arbitrary web site and conduct a phishing attack via a specially crafted URL.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","score":6.1},"cwes":["CWE-601"],"references":["https://groupsession.jp/info/info-news/security202107","https://jvn.jp/en/jp/JVN86026700/index.html","https://groupsession.jp/info/info-news/security202107","https://jvn.jp/en/jp/JVN86026700/index.html"],"products":["groupsession:groupsession","groupsession:groupsession_bycloud","groupsession:groupsession_zion"],"source":"nvd","synced_at":"2026-10-19T21:21:13.713336758+00:00"},"epss":{"cve":"CVE-2021-20789","score":0.00871,"percentile":0.58851,"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."]}