CVE-2021-22873

Name: CVE-2021-22873
Creator: NVD / NIST
Published: 2021-01-26T18:16:19.163+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.1/10EPSS 66.14%

Last modified Jun 17, 2026

CVE-2021-22873 is a medium-severity vulnerability rated 6.1/10 on the CVSS scale. 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. EPSS estimates a 66.14% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

6.1/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

EPSS Probability

66.14%

99.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Revive-Adserver	Revive Adserver	< 5.1.0

References

http://packetstormsecurity.com/files/161070/Revive-Adserver-5.0.5-Cross-Site-Scripting-Open-Redirect.htmlThird Party Advisory, VDB Entry
http://seclists.org/fulldisclosure/2021/Jan/60Broken Link, Mailing List, Third Party Advisory
https://github.com/revive-adserver/revive-adserver/issues/1068Issue Tracking, Third Party Advisory
https://hackerone.com/reports/1081406Exploit, Third Party Advisory
https://www.revive-adserver.com/security/revive-sa-2021-001/Vendor Advisory
http://packetstormsecurity.com/files/161070/Revive-Adserver-5.0.5-Cross-Site-Scripting-Open-Redirect.htmlThird Party Advisory, VDB Entry
http://seclists.org/fulldisclosure/2021/Jan/60Broken Link, Mailing List, Third Party Advisory
https://github.com/revive-adserver/revive-adserver/issues/1068Issue Tracking, Third Party Advisory
https://hackerone.com/reports/1081406Exploit, Third Party Advisory
https://www.revive-adserver.com/security/revive-sa-2021-001/Vendor Advisory

Timeline

Published: Jan 26, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-22873?

How severe is CVE-2021-22873?

CVE-2021-22873 has a CVSS score of 6.1/10 (MEDIUM severity). The EPSS model estimates a 66.14% probability of exploitation in the next 30 days.

How do I fix CVE-2021-22873?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-22873?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST