Language: Go
Label: vulnerable
CWE: CWE-79 \u2014 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

Code:
func CertHandler(c *gin.Context) {
	if strings.Contains(c.Request.UserAgent(), "Firefox") {
		c.Header("content-type", "application/x-x509-ca-cert")
		c.File("ca.cert.cer")
		return
	}
	noFirefoxTemplate.Execute(c.Writer, gin.H{
		"url": "http://" + c.Request.Host + c.Request.URL.String(),
	})
}