# CVE-2013-6171: Auth bypass in n/a

> Local attackers can bypass authentication and access virtual email accounts by exploiting a setuid flaw in Dovecot's checkpassword-reply process.

- **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:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 9 Dec 2013
- **Updated:** 6 Aug 2024
- **Also known as:** DEBIAN-CVE-2013-6171, GHSA-f2q7-xh76-m34j

## What is CVE-2013-6171?

CVE-2013-6171 is a medium-severity authentication bypass vulnerability in Dovecot Dovecot, published on 9 Dec 2013. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

checkpassword-reply in Dovecot before 2.2.7 performs setuid operations to a user who is authenticating, which allows local users to bypass authentication and access virtual email accounts by attaching to the process and using a restricted file descriptor to modify account information in the response to the dovecot-auth server.

Weakness: CWE-287 (Improper Authentication)

## Which versions are affected by CVE-2013-6171?

It affects 1 product.


Products: Dovecot Dovecot.

## How do I fix CVE-2013-6171?

Upgrade to a fixed version.

## Is CVE-2013-6171 being exploited?

There is no known exploitation of CVE-2013-6171 in the wild and no public exploit code.

## Other vulnerabilities in Dovecot Dovecot

- [CVE-2026-24031](https://insights.sbomify.com/CVE-2026-24031/): Auth bypass in OX Dovecot Pro (high 7.7)
- [CVE-2025-59032](https://insights.sbomify.com/CVE-2025-59032/): Denial of service in OX Dovecot Pro (high 7.5)
- [CVE-2026-27858](https://insights.sbomify.com/CVE-2026-27858/): Denial of service in OX Dovecot Pro (high 7.5)
- [CVE-2021-29157](https://insights.sbomify.com/CVE-2021-29157/): Path traversal in n/a (high 7.5)
- [CVE-2020-10957](https://insights.sbomify.com/CVE-2020-10957/): Null dereference in n/a (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2013-6171 and fix it if it is affected.

What it is: CVE-2013-6171 is a medium-severity authentication bypass vulnerability in Dovecot Dovecot, published on 9 Dec 2013. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2013-6171 in the wild and no public exploit code.

Affected product: Dovecot Dovecot. 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-2013-6171/ (Markdown: https://insights.sbomify.com/CVE-2013-6171/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2013-6171
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2013-6171
- OSV: https://osv.dev/vulnerability/CVE-2013-6171

---
From sbomify Insights: https://insights.sbomify.com/CVE-2013-6171/
Summaries are generated and may contain mistakes; the official description above is the record.