# CVE-2021-40865: Unsafe Pre-Authentication Deserialization In Workers

> An unsafe deserialization flaw in Apache Storm worker services allows pre-authentication remote code execution, requiring users to upgrade to patched versions.

- **Severity:** Critical 9.8 (`CVSS:3.1/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:** 25 Oct 2021
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-w729-7633-2fw5

## What is CVE-2021-40865?

CVE-2021-40865 is a critical unsafe deserialization vulnerability in Apache Storm, published on 25 Oct 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An Unsafe Deserialization vulnerability exists in the worker services of the Apache Storm supervisor server allowing pre-auth Remote Code Execution (RCE). Apache Storm 2.2.x users should upgrade to version 2.2.1 or 2.3.0. Apache Storm 2.1.x users should upgrade to version 2.1.1. Apache Storm 1.x users should upgrade to version 1.2.4

Weakness: CWE-502 (Deserialization of Untrusted Data)

## Which versions are affected by CVE-2021-40865?

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


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `org.apache.storm:storm` | Maven | From 1.0.0 | 1.2.4 |
| `org.apache.storm:storm` | Maven | From 1.0.0 | 1.2.4 |
| `org.apache.storm:storm` | Maven | From 2.1.0 | 2.1.1 |
| `org.apache.storm:storm` | Maven | From 2.1.0 | 2.1.1 |
| `org.apache.storm:storm` | Maven | From 2.2.0 | 2.2.1 |
| `org.apache.storm:storm` | Maven | From 2.2.0 | 2.2.1 |

Products: Apache Storm.

## How do I fix CVE-2021-40865?

Upgrade org.apache.storm:storm to a fixed version for your release line: 1.2.4, 2.1.1 or 2.2.1.

## Is CVE-2021-40865 being exploited?

There is no known exploitation of CVE-2021-40865 in the wild and no public exploit code.

Public exploit code:

- CVE-2021-40865 (github_poc): https://github.com/hktalent/CVE-2021-40865

## Other vulnerabilities in Apache Storm

- [CVE-2021-38294](https://insights.sbomify.com/CVE-2021-38294/): Shell Command Injection Vulnerability in Nimbus Thrift Server (critical 9.8)
- [CVE-2018-11779](https://insights.sbomify.com/CVE-2018-11779/): Deserialization of Untrusted Data in Apache Storm (critical 9.8)
- [CVE-2015-3188](https://insights.sbomify.com/CVE-2015-3188/): Apache Storm remote code execution vulnerability (critical 9.8)
- [CVE-2026-35337](https://insights.sbomify.com/CVE-2026-35337/): Apache Storm Client: RCE through Unsafe Deserialization via Kerberos TGT Credential Handling (high 8.8)
- [CVE-2018-1331](https://insights.sbomify.com/CVE-2018-1331/): Code execution in org.apache.storm:storm-core (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-40865 and fix it if it is affected.

What it is: CVE-2021-40865 is a critical unsafe deserialization vulnerability in Apache Storm, published on 25 Oct 2021. 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-2021-40865 in the wild and no public exploit code.

Affected packages and fixed versions:
- org.apache.storm:storm (Maven): affected from 1.0.0; fixed in 1.2.4
- org.apache.storm:storm (Maven): affected from 1.0.0; fixed in 1.2.4
- org.apache.storm:storm (Maven): affected from 2.1.0; fixed in 2.1.1
- org.apache.storm:storm (Maven): affected from 2.1.0; fixed in 2.1.1
- org.apache.storm:storm (Maven): affected from 2.2.0; fixed in 2.2.1
- org.apache.storm:storm (Maven): affected from 2.2.0; fixed in 2.2.1

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-2021-40865/ (Markdown: https://insights.sbomify.com/CVE-2021-40865/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-40865
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-40865
- OSV: https://osv.dev/vulnerability/CVE-2021-40865

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From sbomify Insights: https://insights.sbomify.com/CVE-2021-40865/
Summaries are generated and may contain mistakes; the official description above is the record.