{"cve":"CVE-2021-22873","nvd":{"published":"2021-01-26T18:16:19.163","modified":"2026-06-17T03:37:55.363","status":"Modified","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.","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":["http://packetstormsecurity.com/files/161070/Revive-Adserver-5.0.5-Cross-Site-Scripting-Open-Redirect.html","http://seclists.org/fulldisclosure/2021/Jan/60","https://github.com/revive-adserver/revive-adserver/issues/1068","https://hackerone.com/reports/1081406","https://www.revive-adserver.com/security/revive-sa-2021-001/"],"products":["revive-adserver:revive_adserver"],"source":"nvd","synced_at":"2026-10-19T21:14:10.479542811+00:00"},"epss":{"cve":"CVE-2021-22873","score":0.69561,"percentile":0.99364,"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."]}