On 21 October, two critical vulnerabilities in PHP, known as "PHP2Shell", were disclosed. PHP is a widely used programming language, and these vulnerabilities affected organisations worldwide. We'd like to explain what this meant for Signable and how we responded.
Parts of the Signable platform, including our API and websites, use PHP. We began tracking the vulnerabilities on the morning of 21 October, before security patches were available, and established a dedicated team to coordinate our response.
As a precaution, we removed public access to our internal tools, introduced additional web application firewall protection and monitored our systems for signs of attempted exploitation.
When the PHP project released security patches that afternoon, we immediately began updating our production systems. All customer-facing Signable services were fully patched by 18:40 BST on 21 October.
Our investigation has found no evidence that these vulnerabilities were exploited against Signable. We are completing a further review of our logs against the latest threat intelligence and will contact affected customers directly if our findings change.
No action is required from customers, and Signable services remained available throughout.
As an additional precaution, we are introducing further firewall protections through our hosting provider and reviewing our response to identify opportunities for improvement.
If you have any questions or require further information for a vendor security assessment, please contact help@signable.com.