---
title: "CVE-2021-22873: URL Redirection to Untrusted Site | CubePath"
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…"
language: en
source: https://cubepath.com/security/cve/CVE-2021-22873
---

# CVE-2021-22873: URL Redirection to Untrusted Site | CubePath

## 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.

Official description from the CVE record, published by hackerone. Copyright © 1999-2026 The MITRE Corporation. See [/security/cve/legal](https://cubepath.com/security/cve/legal) for the CVE license. [View the record on cve.org](https://www.cve.org/CVERecord?id=CVE-2021-22873)

## Key data

### EPSS

Exploit Prediction Scoring System by FIRST: an estimate of the probability that exploitation activity will be observed in the next 30 days.

Score

0.69561 (69.6% probability)

Percentile

99.4%

Scores of

Nov 10, 2026

Model

v2026.06.15

### Weakness (CWE)

CWE catalog version 5.0.

CWE names: Copyright © 2006-2026, The MITRE Corporation. See [/security/cve/legal](https://cubepath.com/security/cve/legal) for the CWE license.

- [CWE-601](https://cwe.mitre.org/data/definitions/601.html) URL Redirection to Untrusted Site

## Affected products

Products listed in the CVE record, as the CNA published them.

- https://github.com/revive-adserver/revive-adserver

  - affected: Fixed in 5.1.0

## References

Links listed in the CVE record. They lead to other sites, which CubePath does not control.

- [hackerone.com/reports/1081406](https://hackerone.com/reports/1081406)
- [revive-adserver.com/security/revive-sa-2021-001](https://www.revive-adserver.com/security/revive-sa-2021-001/)
- [github.com/revive-adserver/revive-adserver/issues/1068](https://github.com/revive-adserver/revive-adserver/issues/1068)
- [20210122 \[REVIVE-SA-2021-001\] Revive Adserver Vulnerabilities](http://seclists.org/fulldisclosure/2021/Jan/60)  (seclists.org) mailing-list
- [packetstormsecurity.com/files/161070/Revive-Adserver-5.0.5-…](http://packetstormsecurity.com/files/161070/Revive-Adserver-5.0.5-Cross-Site-Scripting-Open-Redirect.html)

## Timeline

1. ID reserved Jan 6, 2021
2. Record published Jan 21, 2021
3. Record last updated Aug 3, 2024

## Look up another CVE

## About CubePath

CubePath is a cloud provider with data centers in Europe and the United States. It offers VPS, bare metal servers and DDoS protection.

[Cloud VPS](https://cubepath.com/vps) [DDoS protection](https://cubepath.com/ddos-protection)

Data from the CVE Program (MITRE), CISA KEV and FIRST EPSS. CVSS is owned by FIRST and used by permission. Not affiliated with or endorsed by MITRE, CISA or FIRST. Data as of Nov 10, 2026, 20:05 UTC. [Sources and licenses](https://cubepath.com/security/cve/legal)