An attacker can use a Blind SQL injection to retrieve data or stop the MySQL service.
The problem is fixed in 4.2.1
packetstormsecurity.com/files/160539/PrestaShop-ProductComments-4.2.0-SQL-Injection.html
github.com/PrestaShop/productcomments
github.com/PrestaShop/productcomments/commit/7c2033dd811744e021da8897c80d6c301cd45ffa
github.com/PrestaShop/productcomments/releases/tag/v4.2.1
github.com/PrestaShop/productcomments/security/advisories/GHSA-5v44-7647-xfw9
nvd.nist.gov/vuln/detail/CVE-2020-26248
packagist.org/packages/prestashop/productcomments