{"id":"CVE-2021-22873","url":"https://www.cyber-defence.io/tools/cve/CVE-2021-22873","generatedAt":"2026-11-05T01:47:33.493Z","title":"Revive Adserver before 5.1.0 is vulnerable to open redirects via the `dest`, `oadest`, and/or `ct0` parameters of the lg.php and ck.php delivery scripts.","description":"Revive Adserver before 5.1.0 is vulnerable to open redirects via the `dest`, `oadest`, and/or `ct0` parameters of the lg.php and ck.php delivery scripts. Such open redirects had previously been available by design to allow third party ad servers to track such metrics when delivering ads. However, third party click tracking via redirects is not a viable option anymore, leading to such open redirect functionality being removed and reclassified as a vulnerability.","published":"2021-01-26T18:16:19.000Z","lastModified":"2026-06-17T03:37:55.000Z","status":"Modified","sourceIdentifier":"support@hackerone.com","cvss":{"version":"3.1","score":6.1,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"},"cwe":["CWE-601"],"affected":["revive-adserver/revive adserver"],"epss":{"score":0.69561,"percentile":0.99366,"date":"2026-11-03","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"urgent","text":"EPSS puts the probability of exploitation in the next 30 days at 69.6%, higher than 99% of all known CVEs. Patch or mitigate before the next change window."},"changes":[],"references":[{"url":"http://packetstormsecurity.com/files/161070/Revive-Adserver-5.0.5-Cross-Site-Scripting-Open-Redirect.html","tags":["Third Party Advisory","VDB Entry"],"source":"support@hackerone.com"},{"url":"http://seclists.org/fulldisclosure/2021/Jan/60","tags":["Broken Link","Mailing List","Third Party Advisory"],"source":"support@hackerone.com"},{"url":"https://github.com/revive-adserver/revive-adserver/issues/1068","tags":["Issue Tracking","Third Party Advisory"],"source":"support@hackerone.com"},{"url":"https://hackerone.com/reports/1081406","tags":["Exploit","Third Party Advisory"],"source":"support@hackerone.com"},{"url":"https://www.revive-adserver.com/security/revive-sa-2021-001/","tags":["Vendor Advisory"],"source":"support@hackerone.com"},{"url":"http://packetstormsecurity.com/files/161070/Revive-Adserver-5.0.5-Cross-Site-Scripting-Open-Redirect.html","tags":["Third Party Advisory","VDB Entry"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://seclists.org/fulldisclosure/2021/Jan/60","tags":["Broken Link","Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/revive-adserver/revive-adserver/issues/1068","tags":["Issue Tracking","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://hackerone.com/reports/1081406","tags":["Exploit","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.revive-adserver.com/security/revive-sa-2021-001/","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-22873","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."}