# CVE-2012-3376: Client BlockTokens not checked in Apache Hadoop

> Remote attackers with valid Kerberos tickets can bypass block access controls to read or modify arbitrary Hadoop data blocks.

- **Severity:** High 7.5 (`AV:N/AC:L/Au:N/C:P/I:P/A:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 12 Jul 2012
- **Updated:** 6 Aug 2024
- **Also known as:** GHSA-qmh2-h7r6-gm6q

## What is CVE-2012-3376?

CVE-2012-3376 is a high-severity missing authorization vulnerability in n/a, published on 12 Jul 2012. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

DataNodes in Apache Hadoop 2.0.0 alpha does not check the BlockTokens of clients when Kerberos is enabled and the DataNode has checked out the same BlockPool twice from a NodeName, which might allow remote clients to read arbitrary blocks, write to blocks to which they only have read access, and have other unspecified impacts.

Weakness: CWE-310

## Which versions are affected by CVE-2012-3376?

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


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `org.apache.hadoop:hadoop-client` | Maven | From 2.0.0-alpha | 2.0.1-alpha |
| `org.apache.hadoop:hadoop-client` | Maven | From 2.0.0-alpha | 2.0.1-alpha |

Products: Apache Hadoop.

## How do I fix CVE-2012-3376?

Upgrade org.apache.hadoop:hadoop-client to 2.0.1-alpha or later.

## Is CVE-2012-3376 being exploited?

There is no known exploitation of CVE-2012-3376 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2022-25168](https://insights.sbomify.com/CVE-2022-25168/): Command injection in org.apache.hadoop.fs.FileUtil.unTarUsingTar (critical 9.8)
- [CVE-2021-37404](https://insights.sbomify.com/CVE-2021-37404/): Heap buffer overflow in libhdfs native library (critical 9.8)
- [CVE-2022-26612](https://insights.sbomify.com/CVE-2022-26612/): Arbitrary file write in FileUtil#unpackEntries on Windows (critical 9.8)
- [CVE-2019-17195](https://insights.sbomify.com/CVE-2019-17195/): Improper Check for Unusual or Exceptional Conditions in Connect2id Nimbus JOSE+JWT (critical 9.8)
- [CVE-2017-15718](https://insights.sbomify.com/CVE-2017-15718/): Exposure of Sensitive Information in Hadoop (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2012-3376 and fix it if it is affected.

What it is: CVE-2012-3376 is a high-severity missing authorization vulnerability in n/a, published on 12 Jul 2012. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2012-3376 in the wild and no public exploit code.

Affected packages and fixed versions:
- org.apache.hadoop:hadoop-client (Maven): affected from 2.0.0-alpha; fixed in 2.0.1-alpha
- org.apache.hadoop:hadoop-client (Maven): affected from 2.0.0-alpha; fixed in 2.0.1-alpha

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-2012-3376/ (Markdown: https://insights.sbomify.com/CVE-2012-3376/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2012-3376
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2012-3376
- OSV: https://osv.dev/vulnerability/CVE-2012-3376

---
From sbomify Insights: https://insights.sbomify.com/CVE-2012-3376/
Summaries are generated and may contain mistakes; the official description above is the record.