# CVE-2006-2369: Auth bypass in n/a

> Remote attackers can bypass authentication in RealVNC and related products by requesting an insecure security type not offered by the server.

- **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:** No
- **Published:** 15 May 2006
- **Updated:** 7 Aug 2024
- **Also known as:** GHSA-p5jc-gpgq-6vfg

## What is CVE-2006-2369?

CVE-2006-2369 is a high-severity authentication bypass vulnerability in n/a, published on 15 May 2006. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

RealVNC 4.1.1, and other products that use RealVNC such as AdderLink IP and Cisco CallManager, allows remote attackers to bypass authentication via a request in which the client specifies an insecure security type such as "Type 1 - None", which is accepted even if it is not offered by the server, as originally demonstrated using a long password.

Weakness: CWE-287 (Improper Authentication)

## Which versions are affected by CVE-2006-2369?

It affects 1 product.


Products: Vnc Realvnc.

## How do I fix CVE-2006-2369?

No fix has been published for CVE-2006-2369 yet. Limit exposure of the affected software until one is available.

## Is CVE-2006-2369 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2006-2369 exists.

Public exploit code:

- RealVNC 4.1.0 < 4.1.1 - VNC Null Authentication Bypass (Metasploit) (exploitdb)
- RealVNC NULL Authentication Mode Bypass (metasploit)
- RealVNC 4.1.0 < 4.1.1 - VNC Null Authentication Bypass (exploitdb)
- RealVNC - Authentication Bypass (Metasploit) (exploitdb)
- RealVNC 4.1.0/4.1.1 - Authentication Bypass (exploitdb)
- VNC Authentication None Detection (metasploit)

## Other vulnerabilities in n/a

- [CVE-2004-1750](https://insights.sbomify.com/CVE-2004-1750/): Denial of service in n/a (medium 5.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2006-2369 and fix it if it is affected.

What it is: CVE-2006-2369 is a high-severity authentication bypass vulnerability in n/a, published on 15 May 2006. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2006-2369 exists.

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-2006-2369/ (Markdown: https://insights.sbomify.com/CVE-2006-2369/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2006-2369
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2006-2369
- OSV: https://osv.dev/vulnerability/CVE-2006-2369

---
From sbomify Insights: https://insights.sbomify.com/CVE-2006-2369/
Summaries are generated and may contain mistakes; the official description above is the record.