A critical vulnerability is being exploited in Magento 2 and Adobe Commerce sites for online retailers. Attackers are sending trojan orders to the target website and are hiding their attacks by using the increase in online purchases around the time of Black Friday and Cyber Monday sales, and in the holiday shopping period in general. This form of attack has been seen in small numbers throughout most of 2022, however threat researchers at Sansec have concluded that November will see more of these attacks than in the previous 10 months combined, with 38% of all Magento and Adobe Commerce websites being targeted. 

Attackers are exploiting an improper input validation vulnerability, CVE-2022-24086, which Adobe rated as critical in February 2022, when they also released a security patch for this flaw. Attackers first create an account on the target website, and then place an order. This order will contain template code in one of the entry fields, such as ship-to name, or VAT. This code will utilise the unpatched vulnerability and inject JavaScript code, specifically a copy of health_check.php, containing a PHP backdoor for the attackers to use later. This backdoor can run POST request commands and allow the attackers to install a remote access trojan that can steal customer data such as credit card numbers when they make purchases on the infected site. 

Despite a security patch being available for this vulnerability since February, it is estimated that one third of all Magento and Adobe Commerce sites have not applied this update and are therefore vulnerable to these TrojanOrder attacks. As this is a critical severity flaw, with proof of concept (PoC) code that has been available for many months, and is known to be actively exploited, applying the security updates that patch this should be treated as top priority by all ecommerce sites. It is recommended that these sort of high priority updates occur within 3 months of the update release. Any site still using affected versions of Adobe Commerce and Magento Open Source 2.3.3-p1 – 2.3.7-p2 and 2.4.0 – 2.4.3-p1 should update to the latest version immediately.