# CVE-1999-0526: Misconfiguration in n/a

> Attackers can connect to X servers with disabled access control, bypassing authentication to view or interact with the display.

- **Severity:** Critical 10.0 (`AV:N/AC:L/Au:N/C:C/I:C/A:C`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 29 Sep 1999
- **Updated:** 1 Aug 2024
- **Also known as:** GHSA-fv34-2r8h-94mm

## What is CVE-1999-0526?

CVE-1999-0526 is a critical vulnerability in n/a, published on 29 Sep 1999. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An X server's access control is disabled (e.g. through an "xhost +" command) and allows anyone to connect to the server.

## Which versions are affected by CVE-1999-0526?

It affects 1 product.


Products: X.org X11.

## How do I fix CVE-1999-0526?

No fix has been published for CVE-1999-0526 yet. Limit exposure of the affected software until one is available.

## Is CVE-1999-0526 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-1999-0526 exists.

Public exploit code:

- X11 Keylogger (metasploit)
- X11 Keyboard Command Injection (metasploit)
- X11 No-Auth Scanner (metasploit)

## Other vulnerabilities in n/a

- [CVE-2012-2118](https://insights.sbomify.com/CVE-2012-2118/): Memory corruption in n/a (critical 10.0)
- [CVE-2007-1003](https://insights.sbomify.com/CVE-2007-1003/): Integer overflow in n/a (critical 9.0)
- [CVE-2014-8092](https://insights.sbomify.com/CVE-2014-8092/): Integer overflow in n/a (medium 6.5)
- [CVE-2014-8093](https://insights.sbomify.com/CVE-2014-8093/): Integer overflow in n/a (medium 6.5)
- [CVE-2014-8097](https://insights.sbomify.com/CVE-2014-8097/): Memory corruption in n/a (medium 6.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-1999-0526 and fix it if it is affected.

What it is: CVE-1999-0526 is a critical vulnerability in n/a, published on 29 Sep 1999. 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-1999-0526 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-1999-0526/ (Markdown: https://insights.sbomify.com/CVE-1999-0526/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-1999-0526
- NVD: https://nvd.nist.gov/vuln/detail/CVE-1999-0526
- OSV: https://osv.dev/vulnerability/CVE-1999-0526

---
From sbomify Insights: https://insights.sbomify.com/CVE-1999-0526/
Summaries are generated and may contain mistakes; the official description above is the record.