What’s Vulnerable › Vulnerabilities

CVE-2020-27387

• Severity: high (CVSS 8.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 18.5% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2020-11-05 · updated 2026-06-17
• Weakness: CWE-434

Description

An unrestricted file upload issue in HorizontCMS through 1.0.0-beta allows an authenticated remote attacker (with access to the FileManager) to upload and execute arbitrary PHP code by uploading a PHP payload, and then using the FileManager's rename function to provide the payload (which will receive a random name on the server) with the PHP extension, and finally executing the PHP file via an HTTP GET request to /storage/<php_file_name>. NOTE: the vendor has patched this while leaving the version number at 1.0.0-beta.

Affected products

• Horizontcms Project Horizontcms: 1.0.0-alpha, 1.0.0-alpha2, 1.0.0-alpha3, 1.0.0-alpha4, 1.0.0-alpha5, 1.0.0-alpha6 (+3)

References

• http://packetstormsecurity.com/files/160046/HorizontCMS-1.0.0-beta-Shell-Upload.html
• https://blog.vonahi.io/whats-in-a-re-name/
• https://github.com/rapid7/metasploit-framework/pull/14340
• https://github.com/ttimot24/HorizontCMS/commit/436b5ab679fd27afa3d99c023dbe103113da4fee
• http://packetstormsecurity.com/files/160046/HorizontCMS-1.0.0-beta-Shell-Upload.html
• https://blog.vonahi.io/whats-in-a-re-name/
• https://github.com/rapid7/metasploit-framework/pull/14340
• https://github.com/ttimot24/HorizontCMS/commit/436b5ab679fd27afa3d99c023dbe103113da4fee

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