{"id":"CVE-2021-20787","url":"https://www.cyber-defence.io/tools/cve/CVE-2021-20787","generatedAt":"2026-10-27T23:42:30.733Z","title":"Cross-site scripting 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…","description":"Cross-site scripting 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 inject an arbitrary script by sending a specially crafted request to a specific URL.","published":"2021-07-30T14:15:15.000Z","lastModified":"2026-06-17T03:34:27.000Z","status":"Modified","sourceIdentifier":"vultures@jpcert.or.jp","cvss":{"version":"3.1","score":4.8,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N"},"cwe":["CWE-79"],"affected":["groupsession/groupsession","groupsession/groupsession bycloud","groupsession/groupsession zion"],"epss":{"score":0.0064,"percentile":0.50359,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.64%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://groupsession.jp/info/info-news/security202107","tags":["Vendor Advisory"],"source":"vultures@jpcert.or.jp"},{"url":"https://jvn.jp/en/jp/JVN86026700/index.html","tags":["Third Party Advisory"],"source":"vultures@jpcert.or.jp"},{"url":"https://groupsession.jp/info/info-news/security202107","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://jvn.jp/en/jp/JVN86026700/index.html","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-20787","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}