# CVE-2021-43942: Cross-site scripting in Jira Data Center

> Remote attackers can inject arbitrary HTML or JavaScript via a reflected XSS vulnerability in Jira, potentially leading to code execution or account takeover.

- **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:** 4 Jan 2022
- **Updated:** 8 Oct 2024
- **Also known as:** GHSA-jgc7-95gc-23vp

## What is CVE-2021-43942?

CVE-2021-43942 is a medium-severity cross-site scripting vulnerability in Atlassian Jira Server, published on 4 Jan 2022. 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

Affected versions of Atlassian Jira Server and Data Center allow remote attackers to inject arbitrary HTML or JavaScript via a Reflected Cross-Site Scripting (XSS) vulnerability in the /rest/collectors/1.0/template/custom endpoint. To exploit this issue, the attacker must trick a user into visiting a malicious website. The affected versions are before version 8.13.15, and from version 8.14.0 before 8.20.3.

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

## Which versions are affected by CVE-2021-43942?

It affects 2 products.


Products: Atlassian Jira Server, Atlassian Jira Server and Data Center.

## How do I fix CVE-2021-43942?

No fix has been published for CVE-2021-43942 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-43942 being exploited?

There is no known exploitation of CVE-2021-43942 in the wild and no public exploit code.

## Other vulnerabilities in Atlassian Jira Server

- [CVE-2019-11581](https://insights.sbomify.com/CVE-2019-11581/): Atlassian Jira Server and Data Center Server-Side Template Injection (critical 9.8, exploited in the wild)
- [CVE-2019-20400](https://insights.sbomify.com/CVE-2019-20400/): Code injection in Jira Server (high 7.8)
- [CVE-2020-14177](https://insights.sbomify.com/CVE-2020-14177/): Denial of service in Jira Server (medium 6.5)
- [CVE-2019-20401](https://insights.sbomify.com/CVE-2019-20401/): Cross-site request forgery in Jira Server (medium 6.5)
- [CVE-2019-14998](https://insights.sbomify.com/CVE-2019-14998/): Cross-site request forgery in Jira (medium 6.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-43942 and fix it if it is affected.

What it is: CVE-2021-43942 is a medium-severity cross-site scripting vulnerability in Atlassian Jira Server, published on 4 Jan 2022. 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-2021-43942 in the wild and no public exploit code.

Affected product: Atlassian Jira Server. 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-2021-43942/ (Markdown: https://insights.sbomify.com/CVE-2021-43942/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-43942
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-43942
- OSV: https://osv.dev/vulnerability/CVE-2021-43942

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-43942/
Summaries are generated and may contain mistakes; the official description above is the record.