pfSense is a popular open-source firewall solution that has been discovered to have several security vulnerabilities. The most recent scan by SonarCloud found two Cross-Site Scripting (XSS) vulnerabilities and a Command Injection vulnerability in the pfSense Community Edition (CE). These vulnerabilities can be exploited by attackers to execute arbitrary code on the pfSense appliance, spy on local network traffic, or attack services inside the local network. The vulnerabilities were discovered using taint analysis, which is a type of static analysis that tracks data flow from user-controllable data sources to dangerous sinks. SonarCloud found the vulnerabilities in the status_logs_filter_dynamic.php page and the interfaces_gif_edit.php and interfaces_gre_edit.php pages. The vulnerabilities can be patched by encoding/escaping all inserted data for the context it is inserted into, using functions like json_encode() and escapeshellarg(). Netgate has published patch commits and advisories for all issues, and has released patched versions of pfSense Plus 23.09 and pfSense CE 2.7.1. It's recommended to use SonarCloud to find vulnerabilities in your open-source projects and follow the "How to fix it?" tab for each issue.