The method matchCookieDomain() of the Zend_Http_Cookie object has a preg_match() function call, with unescaped input to that call.

When the method gets "/" as $cookieDomain parameter, preg_match() generates following error:

{quote} preg_match(): Unknown modifier '$' {quote}

Current code:

// Check for either exact match or suffix match
return ($cookieDomain == $host ||
     preg_match("/\.$cookieDomain$/", $host));

Proposed fix:

// Check for either exact match or suffix match
return ($cookieDomain == $host ||
     preg_match("/\.".preg_quote($cookieDomain, '/')."$/", $host));