# CVE-2019-11284: Reactor Netty authentication leak in redirects

> Reactor Netty leaks authorization headers during redirects, allowing attackers to steal credentials for other servers.

- **Severity:** Medium 6.8 (`CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 17 Oct 2019
- **Updated:** 16 Sep 2024
- **Also known as:** GHSA-j52r-xc68-q8f4

## What is CVE-2019-11284?

CVE-2019-11284 is a medium-severity vulnerability in Pivotal Reactor Netty, published on 17 Oct 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Pivotal Reactor Netty, versions prior to 0.8.11, passes headers through redirects, including authorization ones. A remote unauthenticated malicious user may gain access to credentials for a different server than they have access to.

Weakness: CWE-522 (Insufficiently Protected Credentials)

## Which versions are affected by CVE-2019-11284?

2 open source packages ship an affected version, including io.projectreactor.netty:reactor-netty. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `io.projectreactor.netty:reactor-netty` | Maven | All versions | 0.8.11 |
| `io.projectreactor.netty:reactor-netty` | Maven | All versions | 0.8.11 |

Products: Broadcom Reactor Netty.

## How do I fix CVE-2019-11284?

Upgrade io.projectreactor.netty:reactor-netty to 0.8.11 or later.

## Is CVE-2019-11284 being exploited?

There is no known exploitation of CVE-2019-11284 in the wild and no public exploit code.

## Other vulnerabilities in Pivotal Reactor Netty

- [CVE-2023-34062](https://insights.sbomify.com/CVE-2023-34062/): In Reactor Netty HTTP Server a malicious user can send a request using a specially crafted URL that can lead to a directory traversal attack (high 7.5)
- [CVE-2020-5403](https://insights.sbomify.com/CVE-2020-5403/): DoS Via Malformed URL with Reactor Netty HTTP Server (medium 6.5)
- [CVE-2020-5404](https://insights.sbomify.com/CVE-2020-5404/): Authentication Leak On Redirect With Reactor Netty HttpClient (medium 6.5)
- [CVE-2026-47848](https://insights.sbomify.com/CVE-2026-47848/): Reactor Netty WebSocket Client Leaks Credentials On Redirect (medium 6.1)
- [CVE-2026-47844](https://insights.sbomify.com/CVE-2026-47844/): Reactor Netty HTTP Server Leaks Exception Details (medium 5.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-11284 and fix it if it is affected.

What it is: CVE-2019-11284 is a medium-severity vulnerability in Pivotal Reactor Netty, published on 17 Oct 2019. 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-2019-11284 in the wild and no public exploit code.

Affected packages and fixed versions:
- io.projectreactor.netty:reactor-netty (Maven): affected all versions; fixed in 0.8.11
- io.projectreactor.netty:reactor-netty (Maven): affected all versions; fixed in 0.8.11

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-2019-11284/ (Markdown: https://insights.sbomify.com/CVE-2019-11284/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-11284
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-11284
- OSV: https://osv.dev/vulnerability/CVE-2019-11284

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-11284/
Summaries are generated and may contain mistakes; the official description above is the record.