# CVE-2019-15849: Auth bypass in n/a

> Attackers can hijack user sessions via fixation to gain unauthorized access and execute commands on HomeMatic CCU3 devices.

- **Severity:** High 7.3 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 17 Oct 2019
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-ppg9-jvvv-qvj4

## What is CVE-2019-15849?

CVE-2019-15849 is a high-severity authentication bypass vulnerability in n/a, published on 17 Oct 2019. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

eQ-3 HomeMatic CCU3 firmware 3.41.11 allows session fixation. An attacker can create session IDs and send them to the victim. After the victim logs in to the session, the attacker can use that session. The attacker could create SSH logins after a valid session and easily compromise the system.

Weakness: CWE-384 (Session Fixation)

## Which versions are affected by CVE-2019-15849?

It affects 1 product.


Products: Eq-3 Homematic Ccu3 Firmware.

## How do I fix CVE-2019-15849?

No fix has been published for CVE-2019-15849 yet. Limit exposure of the affected software until one is available.

## Is CVE-2019-15849 being exploited?

There is no known exploitation of CVE-2019-15849 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2019-15850](https://insights.sbomify.com/CVE-2019-15850/): Missing authorization in n/a (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-15849 and fix it if it is affected.

What it is: CVE-2019-15849 is a high-severity authentication bypass vulnerability in n/a, published on 17 Oct 2019. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2019-15849 in the wild and no public exploit code.

Affected product: n/a. 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-2019-15849/ (Markdown: https://insights.sbomify.com/CVE-2019-15849/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-15849
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-15849
- OSV: https://osv.dev/vulnerability/CVE-2019-15849

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-15849/
Summaries are generated and may contain mistakes; the official description above is the record.