Skip to main content
MEDIUM

CVE-2021-22873

CVSS v3

6.1

MEDIUM

EPSS Score

69.6 %

exploit probability, as of 2026-10-19

CISA KEV

No

known exploited

Exploitation

—

SSVC status

Get an alert for each new CVE published for the software you run.

Set up CVE WatchFree account · no credit card

Affected and fixed versions

Neither OSV.dev nor the vendor advisories we read list affected versions for CVE-2021-22873 yet.

Full record on NVD

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.

Technical details

Published
2021-01-26

Frequently asked questions

What is CVE-2021-22873?

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.

Is CVE-2021-22873 actively exploited?

Active exploitation of CVE-2021-22873 has not been confirmed. Its EPSS score was 69.6% on 2026-10-19, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-22873?

CVE-2021-22873 has a CVSS v3 base score of 6.1 (MEDIUM severity).

Hear about the next vulnerability in your software

CVE Watch matches each new CVE to the vendors and products you list (vendor and product, not the version) and puts it in your alerts with its KEV and EPSS status.

Already have an account? Open CVE WatchNo credit card required · No monthly cap on website lookups · 250 API requests/month