# CVE-2009-4034: Security feature bypass in n/a

> Attackers can bypass SSL hostname verification in PostgreSQL by exploiting null byte handling in X.509 certificates, enabling man-in-the-middle attacks.

- **Severity:** Medium 5.8 (`AV:N/AC:M/Au:N/C:N/I:P/A:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 15 Dec 2009
- **Updated:** 7 Aug 2024
- **Also known as:** GHSA-6wgc-gv8j-fmpq

## What is CVE-2009-4034?

CVE-2009-4034 is a medium-severity vulnerability in Postgresql Postgresql, published on 15 Dec 2009. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

PostgreSQL 7.4.x before 7.4.27, 8.0.x before 8.0.23, 8.1.x before 8.1.19, 8.2.x before 8.2.15, 8.3.x before 8.3.9, and 8.4.x before 8.4.2 does not properly handle a '\0' character in a domain name in the subject's Common Name (CN) field of an X.509 certificate, which (1) allows man-in-the-middle attackers to spoof arbitrary SSL-based PostgreSQL servers via a crafted server certificate issued by a legitimate Certification Authority, and (2) allows remote attackers to bypass intended client-hostname restrictions via a crafted client certificate issued by a legitimate Certification Authority, a related issue to CVE-2009-2408.

Weakness: CWE-310

## Which versions are affected by CVE-2009-4034?

It affects 1 product.


Products: Postgresql Postgresql.

## How do I fix CVE-2009-4034?

Upgrade to a fixed version.

## Is CVE-2009-4034 being exploited?

There is no known exploitation of CVE-2009-4034 in the wild and no public exploit code.

## Other vulnerabilities in Postgresql Postgresql

- [CVE-2013-1902](https://insights.sbomify.com/CVE-2013-1902/): Information disclosure in n/a (critical 10.0)
- [CVE-2013-1903](https://insights.sbomify.com/CVE-2013-1903/): Information disclosure in n/a (critical 10.0)
- [CVE-2007-3279](https://insights.sbomify.com/CVE-2007-3279/): Privilege escalation in n/a (critical 10.0)
- [CVE-2002-1399](https://insights.sbomify.com/CVE-2002-1399/): Integer overflow in n/a (critical 10.0)
- [CVE-2016-3065](https://insights.sbomify.com/CVE-2016-3065/): Information disclosure in n/a (critical 9.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2009-4034 and fix it if it is affected.

What it is: CVE-2009-4034 is a medium-severity vulnerability in Postgresql Postgresql, published on 15 Dec 2009. 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-2009-4034 in the wild and no public exploit code.

Affected product: Postgresql Postgresql. 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-2009-4034/ (Markdown: https://insights.sbomify.com/CVE-2009-4034/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2009-4034
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2009-4034
- OSV: https://osv.dev/vulnerability/CVE-2009-4034

---
From sbomify Insights: https://insights.sbomify.com/CVE-2009-4034/
Summaries are generated and may contain mistakes; the official description above is the record.