# CVE-2012-3544: Apache Tomcat Vulnerable to Denial of Service (DoS) via Improper Handling of chunk extensions

> Remote attackers can cause a denial of service in Apache Tomcat by streaming data with malformed chunk extensions.

- **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:** 1 Jun 2013
- **Updated:** 9 Oct 2026
- **Also known as:** CVE-2013-3544, GHSA-qfxv-3ppc-7qg5

## What is CVE-2012-3544?

CVE-2012-3544 is a medium-severity denial of service vulnerability in Apache Tomcat, published on 1 Jun 2013. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Apache Tomcat 6.x before 6.0.37 and 7.x before 7.0.30 does not properly handle chunk extensions in chunked transfer coding, which allows remote attackers to cause a denial of service by streaming data.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2012-3544?

4 open source packages ship an affected version, including org.apache.tomcat:tomcat. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `org.apache.tomcat:tomcat` | Maven | From 6.0.0 | 6.0.37 |
| `org.apache.tomcat:tomcat` | Maven | From 6.0.0 | 6.0.37 |
| `org.apache.tomcat:tomcat` | Maven | From 7.0.0 | 7.0.30 |
| `org.apache.tomcat:tomcat` | Maven | From 7.0.0 | 7.0.30 |

Products: Apache Tomcat.

## How do I fix CVE-2012-3544?

Upgrade org.apache.tomcat:tomcat to a fixed version for your release line: 6.0.37 or 7.0.30.

## Is CVE-2012-3544 being exploited?

There is no known exploitation of CVE-2012-3544 in the wild and no public exploit code.

## Other vulnerabilities in Apache Tomcat

- [CVE-2025-24813](https://insights.sbomify.com/CVE-2025-24813/): Apache Tomcat Path Equivalence (critical 10.0, exploited in the wild)
- [CVE-2016-8735](https://insights.sbomify.com/CVE-2016-8735/): Apache Tomcat Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2017-12617](https://insights.sbomify.com/CVE-2017-12617/): Apache Tomcat Remote Code Execution (high 8.1, exploited in the wild)
- [CVE-2017-12615](https://insights.sbomify.com/CVE-2017-12615/): Apache Tomcat on Windows Remote Code Execution (high 8.1, exploited in the wild)
- [CVE-2026-34486](https://insights.sbomify.com/CVE-2026-34486/): Apache Tomcat Missing Encryption of Sensitive Data (high 7.5, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2012-3544 and fix it if it is affected.

What it is: CVE-2012-3544 is a medium-severity denial of service vulnerability in Apache Tomcat, published on 1 Jun 2013. 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-2012-3544 in the wild and no public exploit code.

Affected packages and fixed versions:
- org.apache.tomcat:tomcat (Maven): affected from 6.0.0; fixed in 6.0.37
- org.apache.tomcat:tomcat (Maven): affected from 6.0.0; fixed in 6.0.37
- org.apache.tomcat:tomcat (Maven): affected from 7.0.0; fixed in 7.0.30
- org.apache.tomcat:tomcat (Maven): affected from 7.0.0; fixed in 7.0.30

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-2012-3544/ (Markdown: https://insights.sbomify.com/CVE-2012-3544/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2012-3544
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2012-3544
- OSV: https://osv.dev/vulnerability/CVE-2012-3544

---
From sbomify Insights: https://insights.sbomify.com/CVE-2012-3544/
Summaries are generated and may contain mistakes; the official description above is the record.