in src/main/java/org/apache/sling/auth/core/AuthUtil.java [736:754]
public static boolean checkReferer(javax.servlet.http.HttpServletRequest request, String loginForm) {
// SLING-2165: if a Referrer header is supplied check if it matches the login path for this handler
if ("POST".equals(request.getMethod())) {
String referer = request.getHeader("Referer");
if (referer != null) {
String expectedPath = String.format("%s%s", request.getContextPath(), loginForm);
try {
URL uri = new URL(referer);
if (!expectedPath.equals(uri.getPath())) {
// not for this selector, so let the next one handle it.
return false;
}
} catch (MalformedURLException e) {
getLog().debug("Failed to parse the referer value for the login form " + loginForm, e);
}
}
}
return true;
}