# CVE-2016-9877: Auth bypass in Pivotal RabbitMQ 3.x before 3.5.8 and 3.6.x before 3.6.6; RabbitMQ for PCF 1.5.x before 1.5.20, 1.6.x before 1.6.12 and 1.7.x before 1.7.7

> Attackers can bypass MQTT authentication by omitting the password, gaining unauthorized access to the RabbitMQ message broker.

- **Severity:** Critical 9.8 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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:** 29 Dec 2016
- **Updated:** 6 Aug 2024
- **Also known as:** DEBIAN-CVE-2016-9877, DSA-3761-1, GHSA-fjmp-8qvg-p73x, UBUNTU-CVE-2016-9877, USN-3374-1, openSUSE-SU-2024:11294-1

## What is CVE-2016-9877?

CVE-2016-9877 is a critical authentication bypass vulnerability in Broadcom Rabbitmq Server, published on 29 Dec 2016. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An issue was discovered in Pivotal RabbitMQ 3.x before 3.5.8 and 3.6.x before 3.6.6 and RabbitMQ for PCF 1.5.x before 1.5.20, 1.6.x before 1.6.12, and 1.7.x before 1.7.7. MQTT (MQ Telemetry Transport) connection authentication with a username/password pair succeeds if an existing username is provided but the password is omitted from the connection request. Connections that use TLS with a client-provided certificate are not affected.

Weakness: CWE-284 (Improper Access Control)

## Which versions are affected by CVE-2016-9877?

It affects 2 products.


Products: Broadcom Rabbitmq Server, Pivotal Software Rabbitmq.

## How do I fix CVE-2016-9877?

Upgrade to a fixed version.

## Is CVE-2016-9877 being exploited?

There is no known exploitation of CVE-2016-9877 in the wild and no public exploit code.

## Other vulnerabilities in Broadcom Rabbitmq Server

- [CVE-2026-67404](https://insights.sbomify.com/CVE-2026-67404/): RabbitMQ: OAuth2 silent verify_none fallback for JWKS fetch (critical 9.2)
- [CVE-2026-67231](https://insights.sbomify.com/CVE-2026-67231/): RabbitMQ: Trust-store whitelist by Issuer+Serial only (critical 9.1)
- [CVE-2026-57219](https://insights.sbomify.com/CVE-2026-57219/): Information disclosure in rabbitmq-server (high 8.7)
- [CVE-2026-67236](https://insights.sbomify.com/CVE-2026-67236/): RabbitMQ: Plaintext username:password stored in an insecure cookie after successful POST /login (high 8.2)
- [CVE-2026-67409](https://insights.sbomify.com/CVE-2026-67409/): RabbitMQ: JWKS Fetch Ignores HTTP Response Status Code - Signing Key Destruction Causes Authentication DoS (high 8.2)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2016-9877 and fix it if it is affected.

What it is: CVE-2016-9877 is a critical authentication bypass vulnerability in Broadcom Rabbitmq Server, published on 29 Dec 2016. 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-2016-9877 in the wild and no public exploit code.

Affected product: Broadcom Rabbitmq Server. 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-2016-9877/ (Markdown: https://insights.sbomify.com/CVE-2016-9877/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2016-9877
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2016-9877
- OSV: https://osv.dev/vulnerability/CVE-2016-9877

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From sbomify Insights: https://insights.sbomify.com/CVE-2016-9877/
Summaries are generated and may contain mistakes; the official description above is the record.