# CVE-2009-2730: Security feature bypass in n/a

> Man-in-the-middle attackers can spoof SSL servers by exploiting null byte handling in X.509 certificate domain names within the GnuTLS library.

- **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 needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 12 Aug 2009
- **Updated:** 7 Aug 2024
- **Also known as:** GHSA-x6gw-c9hx-x25f, RHSA-2009:1232

## What is CVE-2009-2730?

CVE-2009-2730 is a high-severity vulnerability in Gnu Gnutls, published on 12 Aug 2009. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

libgnutls in GnuTLS before 2.8.2 does not properly handle a '\0' character in a domain name in the subject's (1) Common Name (CN) or (2) Subject Alternative Name (SAN) field of an X.509 certificate, which allows man-in-the-middle attackers to spoof arbitrary SSL servers via a crafted certificate issued by a legitimate Certification Authority.

Weakness: CWE-310

## Which versions are affected by CVE-2009-2730?

It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `gnutls` | Red Hat:enterprise_linux:4::as | All versions | 0:1.0.20-4.el4_8.3 |
| `gnutls-debuginfo` | Red Hat:enterprise_linux:4::as | All versions | 0:1.0.20-4.el4_8.3 |
| `gnutls-devel` | Red Hat:enterprise_linux:4::as | All versions | 0:1.0.20-4.el4_8.3 |
| `gnutls` | Red Hat:enterprise_linux:4::desktop | All versions | 0:1.0.20-4.el4_8.3 |
| `gnutls-debuginfo` | Red Hat:enterprise_linux:4::desktop | All versions | 0:1.0.20-4.el4_8.3 |
| `gnutls-devel` | Red Hat:enterprise_linux:4::desktop | All versions | 0:1.0.20-4.el4_8.3 |
| `gnutls` | Red Hat:enterprise_linux:4::es | All versions | 0:1.0.20-4.el4_8.3 |
| `gnutls-debuginfo` | Red Hat:enterprise_linux:4::es | All versions | 0:1.0.20-4.el4_8.3 |
| `gnutls-devel` | Red Hat:enterprise_linux:4::es | All versions | 0:1.0.20-4.el4_8.3 |
| `gnutls` | Red Hat:enterprise_linux:4::ws | All versions | 0:1.0.20-4.el4_8.3 |
| `gnutls-debuginfo` | Red Hat:enterprise_linux:4::ws | All versions | 0:1.0.20-4.el4_8.3 |
| `gnutls-devel` | Red Hat:enterprise_linux:4::ws | All versions | 0:1.0.20-4.el4_8.3 |
| `gnutls` | Red Hat:enterprise_linux:5::client | All versions | 0:1.4.1-3.el5_3.5 |
| `gnutls-debuginfo` | Red Hat:enterprise_linux:5::client | All versions | 0:1.4.1-3.el5_3.5 |
| `gnutls-utils` | Red Hat:enterprise_linux:5::client | All versions | 0:1.4.1-3.el5_3.5 |
| `gnutls` | Red Hat:enterprise_linux:5::client_workstation | All versions | 0:1.4.1-3.el5_3.5 |
| `gnutls-debuginfo` | Red Hat:enterprise_linux:5::client_workstation | All versions | 0:1.4.1-3.el5_3.5 |
| `gnutls-devel` | Red Hat:enterprise_linux:5::client_workstation | All versions | 0:1.4.1-3.el5_3.5 |
| `gnutls` | Red Hat:enterprise_linux:5::server | All versions | 0:1.4.1-3.el5_3.5 |
| `gnutls-debuginfo` | Red Hat:enterprise_linux:5::server | All versions | 0:1.4.1-3.el5_3.5 |
| `gnutls-devel` | Red Hat:enterprise_linux:5::server | All versions | 0:1.4.1-3.el5_3.5 |
| `gnutls-utils` | Red Hat:enterprise_linux:5::server | All versions | 0:1.4.1-3.el5_3.5 |

Products: Gnu Gnutls.

## How do I fix CVE-2009-2730?

Upgrade to a fixed version.

## Is CVE-2009-2730 being exploited?

There is no known exploitation of CVE-2009-2730 in the wild and no public exploit code.

## Other vulnerabilities in Gnu Gnutls

- [CVE-2008-1948](https://insights.sbomify.com/CVE-2008-1948/): Memory corruption in n/a (critical 10.0)
- [CVE-2017-5334](https://insights.sbomify.com/CVE-2017-5334/): Use after free in n/a (critical 9.8)
- [CVE-2017-5336](https://insights.sbomify.com/CVE-2017-5336/): Memory corruption in n/a (critical 9.8)
- [CVE-2017-5337](https://insights.sbomify.com/CVE-2017-5337/): Memory corruption in n/a (critical 9.8)
- [CVE-2008-1949](https://insights.sbomify.com/CVE-2008-1949/): Null dereference in n/a (critical 9.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2009-2730 and fix it if it is affected.

What it is: CVE-2009-2730 is a high-severity vulnerability in Gnu Gnutls, published on 12 Aug 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-2009-2730 in the wild and no public exploit code.

Affected product: Gnu Gnutls. 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-2009-2730/ (Markdown: https://insights.sbomify.com/CVE-2009-2730/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2009-2730
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2009-2730
- OSV: https://osv.dev/vulnerability/CVE-2009-2730

---
From sbomify Insights: https://insights.sbomify.com/CVE-2009-2730/
Summaries are generated and may contain mistakes; the official description above is the record.