Online upgrade information in some firmware packages of Dahua products is not encrypted. Attackers can obtain this information by analyzing firmware packages by specific means. Affected products include: IPC-HDW1X2X,IPC-HFW1X2X,IPC-HDW2X2X,IPC-HFW2X2X,IPC-HDW4X2X,IPC-HFW4X2X,IPC-HDBW4X2X,IPC-HDW5X2X,IPC-HFW5X2X for versions which Build time is before August 18,2019.