# CVE-2021-43940: Privilege escalation in Confluence Data Center

> Authenticated local attackers can achieve elevated privileges on Windows systems via DLL hijacking in the Confluence installer.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 15 Feb 2022
- **Updated:** 8 Oct 2024
- **Also known as:** GHSA-fv2j-f74f-8cgr

## What is CVE-2021-43940?

CVE-2021-43940 is a high-severity vulnerability in Atlassian Confluence Data Center, published on 15 Feb 2022. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

Affected versions of Atlassian Confluence Server and Data Center allow authenticated local attackers to achieve elevated privileges on the local system via a DLL Hijacking vulnerability in the Confluence installer. This vulnerability only affects installations of Confluence Server and Data Center on Windows. The affected versions are before version 7.4.10, and from version 7.5.0 before 7.12.3.

Weakness: CWE-427 (Uncontrolled Search Path Element)

## Which versions are affected by CVE-2021-43940?

It affects 2 products.


Products: Atlassian Confluence Data Center, Atlassian Confluence Server.

## How do I fix CVE-2021-43940?

No fix has been published for CVE-2021-43940 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-43940 being exploited?

There is no known exploitation of CVE-2021-43940 in the wild and no public exploit code.

## Other vulnerabilities in Atlassian Confluence Data Center

- [CVE-2023-22527](https://insights.sbomify.com/CVE-2023-22527/): Atlassian Confluence Data Center and Server Template Injection (critical 10.0, exploited in the wild)
- [CVE-2023-22518](https://insights.sbomify.com/CVE-2023-22518/): Atlassian Confluence Data Center and Server Improper Authorization (critical 10.0, exploited in the wild)
- [CVE-2023-22515](https://insights.sbomify.com/CVE-2023-22515/): Atlassian Confluence Data Center and Server Broken Access Control (critical 10.0, exploited in the wild)
- [CVE-2022-26134](https://insights.sbomify.com/CVE-2022-26134/): Atlassian Confluence Server and Data Center Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2021-26084](https://insights.sbomify.com/CVE-2021-26084/): Atlassian Confluence Server and Data Center Object-Graph Navigation Language (OGNL) Injection (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-43940 and fix it if it is affected.

What it is: CVE-2021-43940 is a high-severity vulnerability in Atlassian Confluence Data Center, published on 15 Feb 2022. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2021-43940 in the wild and no public exploit code.

Affected product: Atlassian Confluence Data Center. 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-2021-43940/ (Markdown: https://insights.sbomify.com/CVE-2021-43940/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-43940
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-43940
- OSV: https://osv.dev/vulnerability/CVE-2021-43940

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-43940/
Summaries are generated and may contain mistakes; the official description above is the record.