# CVE-2018-18942: RCE in baserCMS before 4.1.4

> Remote attackers can execute arbitrary PHP code by uploading malicious files via the theme configuration logo parameter in baserCMS.

- **Severity:** High 7.2 (`CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 5 Nov 2018
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-rjc2-x53r-6c9r

## What is CVE-2018-18942?

CVE-2018-18942 is a high-severity vulnerability in Basercms Basercms, published on 5 Nov 2018. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

In baserCMS before 4.1.4, lib\Baser\Model\ThemeConfig.php allows remote attackers to execute arbitrary PHP code via the admin/theme_configs/form data[ThemeConfig][logo] parameter.

Weakness: CWE-434 (Unrestricted Upload of File with Dangerous Type)

## Which versions are affected by CVE-2018-18942?

2 open source packages ship an affected version, including baserproject/basercms. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `baserproject/basercms` | Packagist | All versions | 4.1.4 |
| `baserproject/basercms` | Packagist | All versions | 4.1.4 |

Products: Basercms Basercms.

## How do I fix CVE-2018-18942?

Upgrade baserproject/basercms to 4.1.4 or later.

## Is CVE-2018-18942 being exploited?

There is no known exploitation of CVE-2018-18942 in the wild and no public exploit code.

## Other vulnerabilities in Basercms Basercms

- [CVE-2023-25654](https://insights.sbomify.com/CVE-2023-25654/): baserCMS File Uploader Remote Code Execution (RCE) vulnerability (critical 9.8)
- [CVE-2023-25655](https://insights.sbomify.com/CVE-2023-25655/): baserCMS allows any file to be uploaded (critical 9.8)
- [CVE-2017-10842](https://insights.sbomify.com/CVE-2017-10842/): baserCMS SQL Injection vulnerability (critical 9.8)
- [CVE-2026-30880](https://insights.sbomify.com/CVE-2026-30880/): baserCMS: OS command injection vulnerability in installer (critical 9.2)
- [CVE-2026-21861](https://insights.sbomify.com/CVE-2026-21861/): baserCMS: OS Command Injection Leading to Remote Code Execution (RCE) (critical 9.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-18942 and fix it if it is affected.

What it is: CVE-2018-18942 is a high-severity vulnerability in Basercms Basercms, published on 5 Nov 2018. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2018-18942 in the wild and no public exploit code.

Affected packages and fixed versions:
- baserproject/basercms (Packagist): affected all versions; fixed in 4.1.4
- baserproject/basercms (Packagist): affected all versions; fixed in 4.1.4

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-2018-18942/ (Markdown: https://insights.sbomify.com/CVE-2018-18942/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-18942
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-18942
- OSV: https://osv.dev/vulnerability/CVE-2018-18942

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-18942/
Summaries are generated and may contain mistakes; the official description above is the record.