# CVE-2011-4905: Denial of Service in Apache ActiveMQ

> Remote attackers can crash or hang Apache ActiveMQ brokers by exhausting file descriptors via repeated failover connection requests.

- **Severity:** Medium 5.0 (`AV:N/AC:L/Au:N/C:N/I:N/A:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 5 Jan 2012
- **Updated:** 7 Aug 2024
- **Also known as:** DEBIAN-CVE-2011-4905, GHSA-9wcx-326r-7j7w

## What is CVE-2011-4905?

CVE-2011-4905 is a medium-severity denial of service vulnerability in Apache Activemq, published on 5 Jan 2012. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Apache ActiveMQ before 5.6.0 allows remote attackers to cause a denial of service (file-descriptor exhaustion and broker crash or hang) by sending many openwire failover:tcp:// connection requests.

Weakness: CWE-399

## Which versions are affected by CVE-2011-4905?

2 open source packages ship an affected version, including org.apache.activemq:activemq-core. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `org.apache.activemq:activemq-core` | Maven | All versions | 5.6.0 |
| `org.apache.activemq:activemq-core` | Maven | All versions | 5.6.0 |

Products: Apache Activemq.

## How do I fix CVE-2011-4905?

Upgrade org.apache.activemq:activemq-core to 5.6.0 or later.

## Is CVE-2011-4905 being exploited?

There is no known exploitation of CVE-2011-4905 in the wild and no public exploit code.

## Other vulnerabilities in Apache Activemq

- [CVE-2023-46604](https://insights.sbomify.com/CVE-2023-46604/): Apache ActiveMQ Deserialization of Untrusted Data (critical 10.0, exploited in the wild)
- [CVE-2016-3088](https://insights.sbomify.com/CVE-2016-3088/): Apache ActiveMQ Improper Input Validation (critical 9.8, exploited in the wild)
- [CVE-2026-34197](https://insights.sbomify.com/CVE-2026-34197/): Apache ActiveMQ Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2020-11998](https://insights.sbomify.com/CVE-2020-11998/): Remote code execution in Apache ActiveMQ (critical 9.8)
- [CVE-2013-7285](https://insights.sbomify.com/CVE-2013-7285/): Command Injection in Xstream (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2011-4905 and fix it if it is affected.

What it is: CVE-2011-4905 is a medium-severity denial of service vulnerability in Apache Activemq, published on 5 Jan 2012. 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-2011-4905 in the wild and no public exploit code.

Affected packages and fixed versions:
- org.apache.activemq:activemq-core (Maven): affected all versions; fixed in 5.6.0
- org.apache.activemq:activemq-core (Maven): affected all versions; fixed in 5.6.0

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-2011-4905/ (Markdown: https://insights.sbomify.com/CVE-2011-4905/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2011-4905
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2011-4905
- OSV: https://osv.dev/vulnerability/CVE-2011-4905

---
From sbomify Insights: https://insights.sbomify.com/CVE-2011-4905/
Summaries are generated and may contain mistakes; the official description above is the record.