# CVE-2015-3644: Auth bypass in n/a

> Remote attackers can bypass authentication in Stunnel when the redirect option is enabled, allowing unauthorized access to protected services.

- **Severity:** Medium 5.8 (`AV:N/AC:M/Au:N/C:P/I:P/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 14 May 2015
- **Updated:** 6 Aug 2024
- **Also known as:** DEBIAN-CVE-2015-3644, DSA-3299-1, GHSA-3w38-w685-6793, MGASA-2015-0289, SUSE-SU-2015:1062-1, openSUSE-SU-2024:12196-1

## What is CVE-2015-3644?

CVE-2015-3644 is a medium-severity authentication bypass vulnerability in n/a, published on 14 May 2015. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Stunnel 5.00 through 5.13, when using the redirect option, does not redirect client connections to the expected server after the initial connection, which allows remote attackers to bypass authentication.

Weakness: CWE-284 (Improper Access Control)

## Which versions are affected by CVE-2015-3644?

It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `stunnel` | SUSE:Linux Enterprise Server 12 | All versions | 5.00-3.1 |
| `stunnel` | SUSE:Linux Enterprise Server for SAP Applications 12 | All versions | 5.00-3.1 |
| `stunnel` | openSUSE:Tumbleweed | All versions | 5.65-1.1 |

Products: Stunnel Stunnel.

## How do I fix CVE-2015-3644?

Upgrade to a fixed version.

## Is CVE-2015-3644 being exploited?

There is no known exploitation of CVE-2015-3644 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2001-0060](https://insights.sbomify.com/CVE-2001-0060/): Other in n/a (critical 10.0)
- [CVE-2011-2940](https://insights.sbomify.com/CVE-2011-2940/): Memory corruption in n/a (critical 9.3)
- [CVE-2021-20230](https://insights.sbomify.com/CVE-2021-20230/): Auth bypass in stunnel (high 7.5)
- [CVE-2008-2400](https://insights.sbomify.com/CVE-2008-2400/): Unspecified vulnerability in stunnel before 4.23, when running as a service on Windows, allows local users to gain privileges via unknown attack vectors. (high 7.2)
- [CVE-2008-2420](https://insights.sbomify.com/CVE-2008-2420/): Security feature bypass in n/a (medium 6.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2015-3644 and fix it if it is affected.

What it is: CVE-2015-3644 is a medium-severity authentication bypass vulnerability in n/a, published on 14 May 2015. 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-2015-3644 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-2015-3644/ (Markdown: https://insights.sbomify.com/CVE-2015-3644/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2015-3644
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2015-3644
- OSV: https://osv.dev/vulnerability/CVE-2015-3644

---
From sbomify Insights: https://insights.sbomify.com/CVE-2015-3644/
Summaries are generated and may contain mistakes; the official description above is the record.