# CVE-2021-44145: Apache NiFi information disclosure by XXE

> An authenticated user can exploit an XXE vulnerability in the TransformXML processor to reveal sensitive information.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 17 Dec 2021
- **Updated:** 4 Aug 2024
- **Also known as:** BIT-nifi-2021-44145, GHSA-rq96-qhc5-vm4r

## What is CVE-2021-44145?

CVE-2021-44145 is a medium-severity vulnerability in Apache Nifi, published on 17 Dec 2021. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

In the TransformXML processor of Apache NiFi before 1.15.1 an authenticated user could configure an XSLT file which, if it included malicious external entity calls, may reveal sensitive information.

Weakness: CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor)

## Which versions are affected by CVE-2021-44145?

3 open source packages ship an affected version, including org.apache.nifi:nifi and nifi. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `org.apache.nifi:nifi` | Maven | All versions | 1.15.1 |
| `org.apache.nifi:nifi` | Maven | All versions | 1.15.1 |
| `nifi` | Bitnami | From 0.1.0 | 1.15.1 |

Products: Apache Nifi.

## How do I fix CVE-2021-44145?

Upgrade org.apache.nifi:nifi to 1.15.1 or later.

## Is CVE-2021-44145 being exploited?

There is no known exploitation of CVE-2021-44145 in the wild and no public exploit code.

## Other vulnerabilities in Apache Nifi

- [CVE-2018-1309](https://insights.sbomify.com/CVE-2018-1309/): Improper Restriction of XML External Entity Reference in Apache NiFi (critical 9.8)
- [CVE-2017-15697](https://insights.sbomify.com/CVE-2017-15697/): Apache NiFi XSS issue in context path handling (critical 9.8)
- [CVE-2017-5636](https://insights.sbomify.com/CVE-2017-5636/): Injection in Apache NiFi (critical 9.8)
- [CVE-2026-68981](https://insights.sbomify.com/CVE-2026-68981/): Apache NiFi: Uncontrolled Resource Consumption through Decompression of HTTP Requests (high 8.8)
- [CVE-2023-36542](https://insights.sbomify.com/CVE-2023-36542/): Apache NiFi: Potential Code Injection with Properties Referencing Remote Resources (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-44145 and fix it if it is affected.

What it is: CVE-2021-44145 is a medium-severity vulnerability in Apache Nifi, published on 17 Dec 2021. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-44145 in the wild and no public exploit code.

Affected packages and fixed versions:
- org.apache.nifi:nifi (Maven): affected all versions; fixed in 1.15.1
- org.apache.nifi:nifi (Maven): affected all versions; fixed in 1.15.1
- nifi (Bitnami): affected from 0.1.0; fixed in 1.15.1

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-2021-44145/ (Markdown: https://insights.sbomify.com/CVE-2021-44145/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-44145
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-44145
- OSV: https://osv.dev/vulnerability/CVE-2021-44145

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From sbomify Insights: https://insights.sbomify.com/CVE-2021-44145/
Summaries are generated and may contain mistakes; the official description above is the record.