A vulnerability has been found in f3-factory fatfree-core up to 3.9.2. This vulnerability affects the function _curl of the file web.php of the component HTTP Client. Such manipulation leads to improper certificate validation. The attack may be performed from remote. Attacks of this nature are highly complex. It is stated that the exploitability is difficult. Upgrading to version 3.9.3 is able to resolve this issue. The name of the patch is a2c755c8dc9ad0eb7d5fd261b09aff90f649433c. You should upgrade the affected component. The vendor was contacted early, responded in a very professional manner and quickly released a fixed version of the affected product.