CC Quebec Income Tax Calculator Security & Risk Analysis

The "cc-quebec-tax-calculator" plugin, in version 0.2024.1, exhibits a mixed security posture. On the positive side, the plugin demonstrates good practices by using prepared statements for all SQL queries and has no recorded vulnerabilities or CVEs. The static analysis also shows no dangerous functions, file operations, or external HTTP requests, and the attack surface is relatively small with only one shortcode and no unprotected entry points. This suggests a development team that is aware of some security fundamentals.

However, there are significant concerns stemming from the output escaping and nonce/capability checks. A mere 25% of outputs are properly escaped, which is a substantial weakness. This could lead to cross-site scripting (XSS) vulnerabilities if user-provided data is displayed without adequate sanitization, especially given the lack of any recorded nonce or capability checks. The absence of these checks means that even if the shortcode's functionality is limited, any user, authenticated or not (depending on how shortcodes are rendered), could potentially trigger its execution, and improperly escaped output could then be exploited.

The complete lack of taint analysis results is also notable, though it could indicate a lack of complex data flows or that the analysis tools did not identify any. Combined with the low percentage of escaped output and zero capability/nonce checks, the overall risk leans towards potential XSS vulnerabilities, which can have serious security implications for websites. While the plugin has a clean vulnerability history, the identified code signals point to a real and present risk that needs to be addressed.