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Fencer Intel
medium 6.1

CVE-2021-22873 json

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 del…

published 5y ago modified 4mo ago also EUVD-2021-10008

cvss
6.1
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
69.6%
EPSS 69.6% chance of exploitation in 30 days, percentile 99.3%
public exploits
0
none known, plus a Nuclei check

Summary

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.

Patch / fix

  • revive-adserver revive_adserver 5.1.0

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Exploit prediction

69.56% chance of exploitation in the next 30 days, higher than 99.3% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • Nuclei template Revive Adserver <5.1.0 - Open Redirect nuclei detection template
  • hackerone.com https://hackerone.com/reports/1081406 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 6.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
NVD 2.0 5.8 AV:N/AC:M/Au:N/C:P/I:P/A:N

Affected products

  • n/a https://github.com/revive-adserver/revive-adserver

Classification

Weakness
  • CWE-601 URL Redirection to Untrusted Site

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.