Cross-site scripting¶
ID: java/xss Kind: path-problem Security severity: 6.1 Severity: error Precision: high Tags: - security - external/cwe/cwe-079 Query suites: - java-code-scanning.qls - java-security-extended.qls - java-security-and-quality.qls Click to see the query in the CodeQL repository
Directly writing user input (for example, an HTTP request parameter) to a web page, without properly sanitizing the input first, allows for a cross-site scripting vulnerability.
Recommendation¶
To guard against cross-site scripting, consider using contextual output encoding/escaping before writing user input to the page, or one of the other solutions that are mentioned in the reference.
Example¶
The following example shows the page parameter being written directly to the page, leaving the website vulnerable to cross-site scripting.
public class XSS extends HttpServlet { protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // BAD: a request parameter is written directly to the Servlet response stream response.getWriter().print( "The page \"" + request.getParameter("page") + "\" was not found."); } } References¶
Wikipedia: Cross-site scripting.
Common Weakness Enumeration: CWE-79.