# CVE-2013-4434: Information disclosure in n/a

> Remote attackers can enumerate valid usernames on Dropbear SSH servers by analyzing timing differences in failed login error messages.

- **Severity:** Medium 5.0 (`AV:N/AC:L/Au:N/C:P/I:N/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:** 25 Oct 2013
- **Updated:** 6 Aug 2024
- **Also known as:** DEBIAN-CVE-2013-4434, GHSA-7j5m-wjm2-xppv

## What is CVE-2013-4434?

CVE-2013-4434 is a medium-severity vulnerability in n/a, published on 25 Oct 2013. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Dropbear SSH Server before 2013.59 generates error messages for a failed logon attempt with different time delays depending on whether the user account exists, which allows remote attackers to discover valid usernames.

Weakness: CWE-189

## Which versions are affected by CVE-2013-4434?

It affects 1 product.


Products: Dropbear Ssh Project Dropbear Ssh.

## How do I fix CVE-2013-4434?

Upgrade to a fixed version.

## Is CVE-2013-4434 being exploited?

There is no known exploitation of CVE-2013-4434 in the wild and no public exploit code.

Public exploit code:

- Dropbear user enumeration (CVE-2013-4434) PoC (github_poc): https://github.com/styx00/Dropbear_CVE-2013-4434

## Other vulnerabilities in n/a

- [CVE-2016-7406](https://insights.sbomify.com/CVE-2016-7406/): Code injection in n/a (critical 9.8)
- [CVE-2016-7407](https://insights.sbomify.com/CVE-2016-7407/): Code injection in n/a (critical 9.8)
- [CVE-2016-7408](https://insights.sbomify.com/CVE-2016-7408/): Command injection in n/a (high 8.8)
- [CVE-2020-36254](https://insights.sbomify.com/CVE-2020-36254/): Path traversal in n/a (high 8.1)
- [CVE-2007-1099](https://insights.sbomify.com/CVE-2007-1099/): Security feature bypass in n/a (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2013-4434 and fix it if it is affected.

What it is: CVE-2013-4434 is a medium-severity vulnerability in n/a, published on 25 Oct 2013. 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-2013-4434 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-2013-4434/ (Markdown: https://insights.sbomify.com/CVE-2013-4434/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2013-4434
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2013-4434
- OSV: https://osv.dev/vulnerability/CVE-2013-4434

---
From sbomify Insights: https://insights.sbomify.com/CVE-2013-4434/
Summaries are generated and may contain mistakes; the official description above is the record.