# CVE-2021-22872: Cross-site scripting in https://github.com/revive-adserver/revive-adserver

> Reflected XSS in Revive Adserver allows attackers to execute scripts in victim browsers via the afr.php delivery script.

- **Severity:** Medium 6.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 21 Jan 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-xqrq-qgmp-x7x4

## What is CVE-2021-22872?

CVE-2021-22872 is a medium-severity cross-site scripting vulnerability in Revive-Adserver Revive Adserver, published on 21 Jan 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Revive Adserver before 5.1.0 is vulnerable to a reflected cross-site scripting (XSS) vulnerability via the publicly accessible afr.php delivery script. While this issue was previously addressed in modern browsers as CVE-2020-8115, some older browsers (e.g., IE10) that do not automatically URL encode parameters were still vulnerable.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2021-22872?

It affects 1 product.


Products: Revive-Adserver Revive Adserver.

## How do I fix CVE-2021-22872?

No fix has been published for CVE-2021-22872 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-22872 being exploited?

There is no known exploitation of CVE-2021-22872 in the wild and no public exploit code.

## Other vulnerabilities in Revive-Adserver Revive Adserver

- [CVE-2016-9124](https://insights.sbomify.com/CVE-2016-9124/): Security feature bypass in Revive Adserver All versions before 3.2.3 (critical 9.8)
- [CVE-2016-9125](https://insights.sbomify.com/CVE-2016-9125/): Auth bypass in Revive Adserver All versions before 3.2.3 (critical 9.8)
- [CVE-2017-5830](https://insights.sbomify.com/CVE-2017-5830/): Deserialization in n/a (critical 9.8)
- [CVE-2016-9470](https://insights.sbomify.com/CVE-2016-9470/): Other in Revive Adserver All versions before 3.2.5 and 4.0.0 (critical 9.0)
- [CVE-2026-50741](https://insights.sbomify.com/CVE-2026-50741/): Code injection in Adserver (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-22872 and fix it if it is affected.

What it is: CVE-2021-22872 is a medium-severity cross-site scripting vulnerability in Revive-Adserver Revive Adserver, published on 21 Jan 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2021-22872 in the wild and no public exploit code.

Affected product: Revive-Adserver Revive Adserver. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2021-22872/ (Markdown: https://insights.sbomify.com/CVE-2021-22872/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-22872
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-22872
- OSV: https://osv.dev/vulnerability/CVE-2021-22872

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-22872/
Summaries are generated and may contain mistakes; the official description above is the record.