Magento – Security problem: catalog/product_list Error message in system.log

Looking at the block 'catalog/product_list_random` you can only set the number of products to retrieve from the store.

In order get the desired result you want you could create your own custom block that does the following:

$collection = Mage::getResourceModel('catalog/product_collection');
Mage::getModel('catalog/layer')->prepareProductCollection($collection);
$collection->getSelect()->order('rand()');
$collection->addStoreFilter();
$collection->addCategoryFilter($this->getCategoryId())
$numProducts = $this->getNumProducts() ? $this->getNumProducts() : 0;
$collection->setPage(1, $numProducts);

$this->_productCollection = $collection;

To make it work you need to add

<block type="core/text_list" name="product_list.name.after" as="name.after" />
<block type="core/text_list" name="product_list.after" as="after" />

after

<block type="catalog/product_list" name="product_list" template="catalog/product/list.phtml">

in catalog.xml under catalog_category_layered section and copy

app\design\frontend\rwd\default\template\catalog\product\list.phtml

to your theme