Government websites in Europe and elsewhere went offline on Wednesday after the disclosure of critical vulnerabilities in a widely used programming language sent website operators scrambling to protect their systems.
Developers of the PHP programming language said Tuesday they had identified two critical vulnerabilities and urged users to update their sites as soon as a fix was released. With reports that hackers were already exploiting the flaws to break into websites, government agencies in the Netherlands and Finland were among those that took sites offline as a precaution.
PHP underpins large parts of the internet, raising concerns that a significant number of websites could be vulnerable to attack.
"PHP is everywhere. It quietly powers WordPress, Drupal, Joomla, and Magento sites, shared hosting platforms, control panels, and an awful lot of software that doesn't even advertise that it runs PHP under the hood," cybersecurity company Huntress said in a blog post.
Attacks emerging as developers rush to patch vulnerabilities
Dane Knecht, the chief technology officer of Web and cloud security firm Cloudflare, said that attacks were emerging and Cloudflare was updating its firewall rules as a stopgap measure.
"We are seeing early attacks emerging and are updating mitigations as new vectors show up. This is a STOPGAP only. Patch as soon as PHP releases the update," he said on X/Twitter.
Wordfence, a security plugin that protects WordPress websites, said all WordPress sites run on a PHP-installed server. It warned that automatic updates would not apply the fix and advised site owners to find out who is responsible for updating PHP on their sites.
Cybersecurity agencies in Europe, Australia, Japan and Britain have urged PHP users to update immediately or take websites offline until patches can be applied. The Dutch cybersecurity agency itself went offline, saying it had done so as a precaution because of the vulnerabilities.
Officials have said that all PHP versions from PHP 5 onward could be affected, although PHP has not yet disclosed which versions are vulnerable.