# CVE-2023-37303: Denial of service in n/a

> A bug in the MediaWiki CheckUser extension causes user blocking attempts to fail due to database errors, potentially disrupting administrative functions.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 30 Jun 2023
- **Updated:** 27 Nov 2024
- **Also known as:** BIT-mediawiki-2023-37303, GHSA-frhg-fmpg-fqp2, UBUNTU-CVE-2023-37303

## What is CVE-2023-37303?

CVE-2023-37303 is a critical denial of service vulnerability in Mediawiki Mediawiki, published on 30 Jun 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An issue was discovered in the CheckUser extension for MediaWiki through 1.39.3. In certain situations, an attempt to block a user fails after a temporary browser hang and a DBQueryDisconnectedError error message.

Weakness: CWE-754 (Improper Check for Unusual or Exceptional Conditions)

## Which versions are affected by CVE-2023-37303?

1 open source package ship an affected version, including mediawiki. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `mediawiki` | Bitnami | All versions | 1.39.4 |

Products: Mediawiki Mediawiki.

## How do I fix CVE-2023-37303?

Upgrade mediawiki to 1.39.4 or later.

## Is CVE-2023-37303 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-37303 exists.

## Other vulnerabilities in Mediawiki Mediawiki

- [CVE-2022-29904](https://insights.sbomify.com/CVE-2022-29904/): SQL injection in n/a (critical 9.8)
- [CVE-2022-29906](https://insights.sbomify.com/CVE-2022-29906/): Missing authorization in n/a (critical 9.8)
- [CVE-2022-28205](https://insights.sbomify.com/CVE-2022-28205/): Business logic in n/a (critical 9.8)
- [CVE-2022-28206](https://insights.sbomify.com/CVE-2022-28206/): Missing authorization in n/a (critical 9.8)
- [CVE-2022-28209](https://insights.sbomify.com/CVE-2022-28209/): Missing authorization in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-37303 and fix it if it is affected.

What it is: CVE-2023-37303 is a critical denial of service vulnerability in Mediawiki Mediawiki, published on 30 Jun 2023. 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-2023-37303 exists.

Affected packages and fixed versions:
- mediawiki (Bitnami): affected all versions; fixed in 1.39.4

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-2023-37303/ (Markdown: https://insights.sbomify.com/CVE-2023-37303/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-37303
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-37303
- OSV: https://osv.dev/vulnerability/CVE-2023-37303

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-37303/
Summaries are generated and may contain mistakes; the official description above is the record.