# CVE-2021-40336: HTTP Response Splitting in Hitachi Energy’s MSM Product

> Attackers can exploit HTTP response splitting in the MSM web interface to steal session cookies or deliver malicious code to users.

- **Severity:** Medium 5.0 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 25 Jul 2022
- **Updated:** 17 Sep 2024
- **Also known as:** GHSA-3885-gg9g-8j6j

## What is CVE-2021-40336?

CVE-2021-40336 is a medium-severity vulnerability in Hitachi Energy MSM, published on 25 Jul 2022. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

A vulnerability exists in the http web interface where the web interface does not validate data in an HTTP header. This causes a possible HTTP response splitting, which if exploited could lead an attacker to channel down harmful code into the user’s web browser, such as to steal the session cookies. Thus, an attacker who successfully makes an MSM user who has already established a session to MSM web interface clicks a forged link to the MSM web interface, e.g., the link is sent per E-Mail, could trick the user into downloading malicious software onto his computer. This issue affects: Hitachi Energy MSM V2.2 and prior versions.

Weakness: CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component), CWE-113 (Improper Neutralization of CRLF Sequences in HTTP Headers)

## Which versions are affected by CVE-2021-40336?

It affects 1 product.


Products: Hitachienergy Modular Switchgear Monitoring Firmware.

## How do I fix CVE-2021-40336?

No fix has been published for CVE-2021-40336 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-40336 being exploited?

There is no known exploitation of CVE-2021-40336 in the wild and no public exploit code.

## Other vulnerabilities in Hitachi Energy MSM

- [CVE-2021-40335](https://insights.sbomify.com/CVE-2021-40335/): Cross Site Request Forgery (CSRF) in Hitachi Energy’s MSM Product (medium 5.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-40336 and fix it if it is affected.

What it is: CVE-2021-40336 is a medium-severity vulnerability in Hitachi Energy MSM, published on 25 Jul 2022. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2021-40336 in the wild and no public exploit code.

Affected product: Hitachi Energy MSM. 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-2021-40336/ (Markdown: https://insights.sbomify.com/CVE-2021-40336/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-40336
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-40336
- OSV: https://osv.dev/vulnerability/CVE-2021-40336

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-40336/
Summaries are generated and may contain mistakes; the official description above is the record.