# CVE-2018-17194: Apache NiFi Improper Input Validation vulnerability

> Attackers can cause cluster nodes to hang and timeout by sending DELETE requests with non-zero Content-Length headers, requiring an upgrade to fix.

- **Severity:** High 7.5 (`CVSS:3.0/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:** 19 Dec 2018
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-43fp-vwwg-qgv6

## What is CVE-2018-17194?

CVE-2018-17194 is a high-severity denial of service vulnerability in Apache Nifi, published on 19 Dec 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

When a client request to a cluster node was replicated to other nodes in the cluster for verification, the Content-Length was forwarded. On a DELETE request, the body was ignored, but if the initial request had a Content-Length value other than 0, the receiving nodes would wait for the body and eventually timeout. Mitigation: The fix to check DELETE requests and overwrite non-zero Content-Length header values was applied on the Apache NiFi 1.8.0 release. Users running a prior 1.x release should upgrade to the appropriate release.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2018-17194?

2 open source packages ship an affected version, including org.apache.nifi:nifi-framework-cluster. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `org.apache.nifi:nifi-framework-cluster` | Maven | From 1.0.0 | 1.8.0 |
| `org.apache.nifi:nifi-framework-cluster` | Maven | From 1.0.0 | 1.8.0 |

Products: Apache Nifi.

## How do I fix CVE-2018-17194?

Upgrade org.apache.nifi:nifi-framework-cluster to 1.8.0 or later.

## Is CVE-2018-17194 being exploited?

There is no known exploitation of CVE-2018-17194 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-2018-17194 and fix it if it is affected.

What it is: CVE-2018-17194 is a high-severity denial of service vulnerability in Apache Nifi, published on 19 Dec 2018. 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-2018-17194 in the wild and no public exploit code.

Affected packages and fixed versions:
- org.apache.nifi:nifi-framework-cluster (Maven): affected from 1.0.0; fixed in 1.8.0
- org.apache.nifi:nifi-framework-cluster (Maven): affected from 1.0.0; fixed in 1.8.0

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-2018-17194/ (Markdown: https://insights.sbomify.com/CVE-2018-17194/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-17194
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-17194
- OSV: https://osv.dev/vulnerability/CVE-2018-17194

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-17194/
Summaries are generated and may contain mistakes; the official description above is the record.