# CVE-2023-2023: Custom 404 Pro < 3.7.3 - Reflected Cross-Site Scripting

> Attackers can execute arbitrary scripts in victim browsers via unescaped URLs in the Custom 404 Pro WordPress plugin.

- **Severity:** Medium 6.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 30 May 2023
- **Updated:** 9 Jan 2025
- **Also known as:** GHSA-2h88-qxq3-v97j

## What is CVE-2023-2023?

CVE-2023-2023 is a medium-severity cross-site scripting vulnerability in Unknown Custom 404 Pro, published on 30 May 2023. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

The Custom 404 Pro WordPress plugin before 3.7.3 does not escape some URLs before outputting them in attributes, leading to Reflected Cross-Site Scripting.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

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

It affects 1 product.


Products: Kunalnagar Custom 404 Pro.

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

No fix has been published for CVE-2023-2023 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-2023 being exploited?

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

Public exploit code:

- HW2023@POC@EXP@CVE-2023-2023 (github_poc): https://github.com/thatformat/Hvv2023
- https://github.com/druxter-x/PHP-CVE-2023-2023-2640-POC-Escalation (github_poc): https://github.com/druxter-x/PHP-CVE-2023-2023-2640-POC-Escalation
- Custom 404 Pro < 3.7.3 - Cross-Site Scripting (nuclei): http/cves/2023/CVE-2023-2023.yaml

## Other vulnerabilities in Unknown Custom 404 Pro

- [CVE-2023-2032](https://insights.sbomify.com/CVE-2023-2032/): Custom 404 Pro < 3.8.1 - Multiple SQL Injection (critical 9.8)
- [CVE-2022-47605](https://insights.sbomify.com/CVE-2022-47605/): WordPress Custom 404 Pro Plugin <= 3.7.0 is vulnerable to SQL Injection (SQLi) (high 8.3)
- [CVE-2024-39646](https://insights.sbomify.com/CVE-2024-39646/): WordPress Custom 404 Pro plugin <= 3.11.1 - Reflected Cross Site Scripting (XSS) vulnerability (high 7.1)
- [CVE-2023-51540](https://insights.sbomify.com/CVE-2023-51540/): WordPress Custom 404 Pro Plugin <= 3.10.0 is vulnerable to Cross Site Scripting (XSS) (high 7.1)
- [CVE-2019-15838](https://insights.sbomify.com/CVE-2019-15838/): Cross-site scripting in n/a (medium 6.1)

## Fix prompt for AI coding agents

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

What it is: CVE-2023-2023 is a medium-severity cross-site scripting vulnerability in Unknown Custom 404 Pro, published on 30 May 2023. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-2023 exists.

Affected product: Unknown Custom 404 Pro. 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-2023-2023/ (Markdown: https://insights.sbomify.com/CVE-2023-2023/index.md)
```

## Sources

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

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