Impact

When rendering validation error messages via the formElementErrors() view helper shipped with laminas-form, many messages will contain the submitted value. However, in vulnerable versions of laminas-form, the value was not being escaped for HTML contexts, which can potentially lead to a Reflected Cross-Site Scripting (XSS) attack.

Patches

The following versions were issued to mitigate the vulnerability:

- 2.17.1 - 3.0.2 - 3.1.1

Workarounds

At the top of a view script where you call the formElementErrors() view helper, place the following code:

php use Laminas\Form\ElementInterface; use Laminas\View\PhpRenderer;

$escapeMessages = function (ElementInterface $formOrElement, PhpRenderer $renderer): void { $messages = $element->getMessages(); if (! $messages) { return; }

$escaped = []; arraywalkrecursive( $messages, static function (string $item) use (&$escaped, $renderer): void { $escaped[] = $renderer->escapeHtml($item); } };

$element->setMessages($escaped); };

Before calling formElementErrors() with a form, fieldset, or element, call the above closure as follows

php // Usage with a form // $this is the view renderer $escapeMessages($form, $this);

// Usage with a fieldset // $this is the view renderer $escapeMessages($fieldset, $this);

// Usage with a form element // $this is the view renderer $escapeMessages($element, $this);

For more information

If you have any questions or comments about this advisory:

Open an issue Email us at security@getlaminas.org