Security Advisory
CVE-2021-47870
CVE vulnerability detail — eXtreme Datacenter Security Operations
Description
GetSimple CMS My SMTP Contact Plugin 1.1.2 suffers from a Stored Cross-Site Scripting (XSS) vulnerability. The plugin attempts to sanitize user input using htmlspecialchars(), but this can be bypassed by passing dangerous characters as escaped hex bytes. This allows attackers to inject arbitrary client-side code that executes in the administrators browser when visiting a malicious page.