What’s Vulnerable › Vulnerabilities

CVE-2021-23836

• Severity: medium (CVSS 4.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.9% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2021-01-15 · updated 2026-06-17
• Weakness: CWE-79

Description

An issue was discovered in flatCore before 2.0.0 build 139. A stored XSS vulnerability was identified in the prefs_smtp_psw HTTP request body parameter for the acp interface. An admin user can inject malicious client-side script into the affected parameter without any form of input sanitization. The injected payload will be executed in the browser of a user whenever one visits the affected module page.

Affected products

• Flatcore: through 2.0.0

References

• http://packetstormsecurity.com/files/160936/flatCore-CMS-XSS-File-Disclosure-SQL-Injection.html
• https://github.com/flatCore/flatCore-CMS
• https://sec-consult.com/vulnerability-lab/
• http://packetstormsecurity.com/files/160936/flatCore-CMS-XSS-File-Disclosure-SQL-Injection.html
• https://github.com/flatCore/flatCore-CMS
• https://sec-consult.com/vulnerability-lab/

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