# CVE-2012-6063: Use after free in n/a

> A double free vulnerability in libssh allows remote attackers to cause a crash and potentially execute arbitrary code.

- **Severity:** High 7.5 (`AV:N/AC:L/Au:N/C:P/I:P/A:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Not stated
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 30 Nov 2012
- **Updated:** 6 Aug 2024
- **Also known as:** DEBIAN-CVE-2012-6063, GHSA-fgm4-g835-pxpp

## What is CVE-2012-6063?

CVE-2012-6063 is a high-severity use after free vulnerability in n/a, published on 30 Nov 2012. It can be exploited over the network, with no action from the victim.

### Official description

Double free vulnerability in the sftp_mkdir function in sftp.c in libssh before 0.5.3 allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via unspecified vectors, a different vector than CVE-2012-4559.

Weakness: CWE-399

## Which versions are affected by CVE-2012-6063?

It affects 1 product.


Products: Libssh Libssh.

## How do I fix CVE-2012-6063?

Upgrade to a fixed version.

## Is CVE-2012-6063 being exploited?

There is no known exploitation of CVE-2012-6063 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2026-59851](https://insights.sbomify.com/CVE-2026-59851/): Libssh: libssh: authentication bypass via missing gssapi principal check (high 8.8)
- [CVE-2025-5987](https://insights.sbomify.com/CVE-2025-5987/): Libssh: invalid return code for chacha20 poly1305 with openssl backend (high 8.1)
- [CVE-2025-14821](https://insights.sbomify.com/CVE-2025-14821/): Libssh: libssh: insecure default configuration leads to local man-in-the-middle attacks on windows (high 7.8)
- [CVE-2012-4560](https://insights.sbomify.com/CVE-2012-4560/): Memory corruption in n/a (high 7.5)
- [CVE-2012-4562](https://insights.sbomify.com/CVE-2012-4562/): Integer overflow in n/a (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2012-6063 and fix it if it is affected.

What it is: CVE-2012-6063 is a high-severity use after free vulnerability in n/a, published on 30 Nov 2012. It can be exploited over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2012-6063 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-2012-6063/ (Markdown: https://insights.sbomify.com/CVE-2012-6063/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2012-6063
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2012-6063
- OSV: https://osv.dev/vulnerability/CVE-2012-6063

---
From sbomify Insights: https://insights.sbomify.com/CVE-2012-6063/
Summaries are generated and may contain mistakes; the official description above is the record.