# CVE-2020-25697: Auth bypass in xorg-x11-server

> Attackers can escalate privileges and execute code by impersonating the X server due to missing client authentication in Xorg-x11-server.

- **Severity:** High 7.0 (`CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **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:** 26 May 2021
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-qrj9-jg63-p8hg, SUSE-SU-2023:3189-1, SUSE-SU-2023:3190-1, UBUNTU-CVE-2020-25697, openSUSE-SU-2024:12993-1

## What is CVE-2020-25697?

CVE-2020-25697 is a high-severity authentication bypass vulnerability in X.org X Server, published on 26 May 2021. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A privilege escalation flaw was found in the Xorg-x11-server due to a lack of authentication for X11 clients. This flaw allows an attacker to take control of an X application by impersonating the server it is expecting to connect to.

Weakness: CWE-306 (Missing Authentication for Critical Functionality)

## Which versions are affected by CVE-2020-25697?

It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `xtrans` | SUSE:Linux Enterprise Module for Basesystem 15 SP4 | All versions | 1.3.5-150000.3.3.1 |
| `xtrans` | SUSE:Linux Enterprise Module for Basesystem 15 SP5 | All versions | 1.3.5-150000.3.3.1 |
| `xtrans` | SUSE:Linux Enterprise Real Time 15 SP3 | All versions | 1.3.5-150000.3.3.1 |
| `xtrans` | SUSE:Linux Enterprise Software Development Kit 12 SP5 | All versions | 1.3.5-5.3.1 |
| `xtrans` | openSUSE:Leap 15.4 | All versions | 1.3.5-150000.3.3.1 |
| `xtrans` | openSUSE:Leap 15.5 | All versions | 1.3.5-150000.3.3.1 |
| `xtrans` | openSUSE:Tumbleweed | All versions | 1.5.0-1.1 |

Products: X.org X Server.

## How do I fix CVE-2020-25697?

Apply the vendor's patch.

## Is CVE-2020-25697 being exploited?

There is no known exploitation of CVE-2020-25697 in the wild and no public exploit code.

## Other vulnerabilities in X.org X Server

- [CVE-2026-56000](https://insights.sbomify.com/CVE-2026-56000/): xorg-x11-server / xwayland GLX contextTags Use-After-Free in CommonMakeCurrent() (critical 9.0)
- [CVE-2017-10971](https://insights.sbomify.com/CVE-2017-10971/): Memory corruption in n/a (high 8.8)
- [CVE-2026-55999](https://insights.sbomify.com/CVE-2026-55999/): xorg-server / xwayland glamor font atlas Heap Buffer Overflow (high 8.5)
- [CVE-2022-2319](https://insights.sbomify.com/CVE-2022-2319/): Memory corruption in xorg-x11-server (high 7.8)
- [CVE-2022-2320](https://insights.sbomify.com/CVE-2022-2320/): Memory corruption in xorg-x11-server (high 7.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-25697 and fix it if it is affected.

What it is: CVE-2020-25697 is a high-severity authentication bypass vulnerability in X.org X Server, published on 26 May 2021. 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-2020-25697 in the wild and no public exploit code.

Affected product: X.org X Server. 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-2020-25697/ (Markdown: https://insights.sbomify.com/CVE-2020-25697/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-25697
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-25697
- OSV: https://osv.dev/vulnerability/CVE-2020-25697

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-25697/
Summaries are generated and may contain mistakes; the official description above is the record.