# CVE-2009-2939: Path traversal in n/a

> Local attackers can exploit symlink vulnerabilities in Postfix PID directory permissions to overwrite arbitrary files and potentially escalate privileges.

- **Severity:** Medium 6.9 (`AV:L/AC:M/Au:N/C:C/I:C/A:C`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 21 Sep 2009
- **Updated:** 7 Aug 2024
- **Also known as:** DEBIAN-CVE-2009-2939, GHSA-rpqw-5g6j-x944

## What is CVE-2009-2939?

CVE-2009-2939 is a medium-severity path traversal vulnerability in n/a, published on 21 Sep 2009. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

The postfix.postinst script in the Debian GNU/Linux and Ubuntu postfix 2.5.5 package grants the postfix user write access to /var/spool/postfix/pid, which might allow local users to conduct symlink attacks that overwrite arbitrary files.

Weakness: CWE-59 (Improper Link Resolution Before File Access)

## Which versions are affected by CVE-2009-2939?

It affects 1 product.


Products: Postfix Postfix.

## How do I fix CVE-2009-2939?

Apply the vendor's patch.

## Is CVE-2009-2939 being exploited?

There is no known exploitation of CVE-2009-2939 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2017-10140](https://insights.sbomify.com/CVE-2017-10140/): Privilege escalation in n/a (high 7.8)
- [CVE-2008-4977](https://insights.sbomify.com/CVE-2008-4977/): Path traversal in n/a (medium 6.9)
- [CVE-2011-1720](https://insights.sbomify.com/CVE-2011-1720/): Memory corruption in n/a (medium 6.8)
- [CVE-2011-0411](https://insights.sbomify.com/CVE-2011-0411/): Security feature bypass in n/a (medium 6.8)
- [CVE-2012-0811](https://insights.sbomify.com/CVE-2012-0811/): SQL injection in n/a (medium 6.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2009-2939 and fix it if it is affected.

What it is: CVE-2009-2939 is a medium-severity path traversal vulnerability in n/a, published on 21 Sep 2009. 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-2009-2939 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-2009-2939/ (Markdown: https://insights.sbomify.com/CVE-2009-2939/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2009-2939
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2009-2939
- OSV: https://osv.dev/vulnerability/CVE-2009-2939

---
From sbomify Insights: https://insights.sbomify.com/CVE-2009-2939/
Summaries are generated and may contain mistakes; the official description above is the record.