Language: PHP
Label: safe
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:
    public function validate($uri, $config, $context)
    {
        if ($config->get('URI.Disable')) {
            return false;
        }

        $uri = $this->parseCDATA($uri);

        // parse the URI
        $uri = $this->parser->parse($uri);
        if ($uri === false) {
            return false;
        }

        // add embedded flag to context for validators
        $context->register('EmbeddedURI', $this->embedsResource);

        $ok = false;
        do {

            // generic validation
            $result = $uri->validate($config, $context);
            if (!$result) {
                break;
            }

            // chained filtering
            $uri_def = $config->getDefinition('URI');
            $result = $uri_def->filter($uri, $config, $context);
            if (!$result) {
                break;
            }

            // scheme-specific validation
            $scheme_obj = $uri->getSchemeObj($config, $context);
            if (!$scheme_obj) {
                break;
            }
            if ($this->embedsResource && !$scheme_obj->browsable) {
                break;
            }
            $result = $scheme_obj->validate($uri, $config, $context);
            if (!$result) {
                break;
            }

            // Post chained filtering
            $result = $uri_def->postFilter($uri, $config, $context);
            if (!$result) {
                break;
            }

            // survived gauntlet
            $ok = true;

        } while (false);

        $context->destroy('EmbeddedURI');
        if (!$ok) {
            return false;
        }
        // back to string
        return $uri->toString();
    }