# CVE-2020-9487: Missing Authentication for Critical Function in Apache NiFi

> Unauthenticated attackers can exhaust download token resources in Apache NiFi, preventing legitimate users from accessing content.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 1 Oct 2020
- **Updated:** 4 Aug 2024
- **Also known as:** BIT-nifi-2020-9487, GHSA-3pp3-77j6-8ph6

## What is CVE-2020-9487?

CVE-2020-9487 is a high-severity denial of service vulnerability in Apache Nifi, published on 1 Oct 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In Apache NiFi 1.0.0 to 1.11.4, the NiFi download token (one-time password) mechanism used a fixed cache size and did not authenticate a request to create a download token, only when attempting to use the token to access the content. An unauthenticated user could repeatedly request download tokens, preventing legitimate users from requesting download tokens.

Weakness: CWE-306 (Missing Authentication for Critical Functionality)

## Which versions are affected by CVE-2020-9487?

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 | From 1.0.0 | 1.12.0-RC1 |
| `org.apache.nifi:nifi` | Maven | From 1.0.0 | 1.12.0-RC1 |
| `nifi` | Bitnami | From 1.0.0 to 1.11.4 | None |

Products: Apache Nifi.

## How do I fix CVE-2020-9487?

Upgrade org.apache.nifi:nifi to 1.12.0-RC1 or later.

## Is CVE-2020-9487 being exploited?

There is no known exploitation of CVE-2020-9487 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-2020-9487 and fix it if it is affected.

What it is: CVE-2020-9487 is a high-severity denial of service vulnerability in Apache Nifi, published on 1 Oct 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2020-9487 in the wild and no public exploit code.

Affected packages and fixed versions:
- org.apache.nifi:nifi (Maven): affected from 1.0.0; fixed in 1.12.0-RC1
- org.apache.nifi:nifi (Maven): affected from 1.0.0; fixed in 1.12.0-RC1
- nifi (Bitnami): affected from 1.0.0 up to 1.11.4; no fix listed

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-2020-9487/ (Markdown: https://insights.sbomify.com/CVE-2020-9487/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-9487
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-9487
- OSV: https://osv.dev/vulnerability/CVE-2020-9487

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From sbomify Insights: https://insights.sbomify.com/CVE-2020-9487/
Summaries are generated and may contain mistakes; the official description above is the record.