# CVE-2013-4548: Security feature bypass in n/a

> Authenticated users can bypass ForceCommand and login-shell restrictions in OpenSSH when using AES-GCM ciphers due to improper memory initialization.

- **Severity:** Medium 6.0 (`AV:N/AC:M/Au:S/C:P/I:P/A:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 8 Nov 2013
- **Updated:** 6 Aug 2024
- **Also known as:** DEBIAN-CVE-2013-4548, GHSA-wg6r-5vgg-89fv

## What is CVE-2013-4548?

CVE-2013-4548 is a medium-severity vulnerability in OpenSSH, published on 8 Nov 2013. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

The mm_newkeys_from_blob function in monitor_wrap.c in sshd in OpenSSH 6.2 and 6.3, when an AES-GCM cipher is used, does not properly initialize memory for a MAC context data structure, which allows remote authenticated users to bypass intended ForceCommand and login-shell restrictions via packet data that provides a crafted callback address.

Weakness: CWE-264

## Which versions are affected by CVE-2013-4548?

It affects 1 product.


Products: OpenSSH.

## How do I fix CVE-2013-4548?

Upgrade to a fixed version.

## Is CVE-2013-4548 being exploited?

There is no known exploitation of CVE-2013-4548 in the wild and no public exploit code.

## Other vulnerabilities in OpenSSH

- [CVE-2003-0786](https://insights.sbomify.com/CVE-2003-0786/): Auth bypass in n/a (critical 10.0)
- [CVE-2003-0693](https://insights.sbomify.com/CVE-2003-0693/): Memory corruption in n/a (critical 10.0)
- [CVE-2002-0640](https://insights.sbomify.com/CVE-2002-0640/): Memory corruption in n/a (critical 10.0)
- [CVE-2001-0144](https://insights.sbomify.com/CVE-2001-0144/): Integer overflow in n/a (critical 10.0)
- [CVE-2000-0999](https://insights.sbomify.com/CVE-2000-0999/): Memory corruption in n/a (critical 10.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2013-4548 and fix it if it is affected.

What it is: CVE-2013-4548 is a medium-severity vulnerability in OpenSSH, published on 8 Nov 2013. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2013-4548 in the wild and no public exploit code.

Affected product: OpenSSH. 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-2013-4548/ (Markdown: https://insights.sbomify.com/CVE-2013-4548/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2013-4548
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2013-4548
- OSV: https://osv.dev/vulnerability/CVE-2013-4548

---
From sbomify Insights: https://insights.sbomify.com/CVE-2013-4548/
Summaries are generated and may contain mistakes; the official description above is the record.