Cybercriminals are targeting Magento sites running Mirasvit Helpdesk - a popular helpdesk extension. The extension enables site owners to add a "Chat with us" widget on their Magento shops. Mirasvit was vulnerable to security flaws that affect every version of the extension up until version 1.5.2. Security firm WebShield had first published details about these security bugs back in September. While the developers had delivered a prompt fix and released version 1.5.3 in the same month, it appears websites are still using the vulnerable versions.
In a latest report, security researcher Willem de Groot has revealed that hackers are exploiting both these vulnerabilities with a goal to steal payment card data from the affected stores.
"This attack is particularly sophisticated, as it is able to bypass many security measures that a merchant might have taken. For example, IP restriction on the backend, strong passwords, 2-Factor-Authentication and using a VPN tunnel will not block this attack."
The first vulnerability was a cross-site scripting issue (CVE-2017-14321), while the second one enables attackers to upload files to the underlying Magento servers (CVE-2017-14320). Researcher said that attackers can insert additional malicious code in the store's footer section that would execute on all of the store's pages, with an intention to collect payment card data from the store's checkout process.
Attackers first send messages through the Mirasvit Helpdesk widget that included the malicious code carrying the XSS payload and a message for the service representatives. This message would store in the Magento database, however, when the support staff would check it, it would appear as a benign text, something like:
Hey, I strongly recommend you to make a redesign! Please contact me if you need a good designer! – email@example.com
While the malicious code wasn't visible, as soon as it's viewed, the payload is executed which then starts stealing payment card data.