An issue was discovered in the Hyundai Gen5W_L in-vehicle infotainment system AE_E_PE_EUR.S5W_L001.001.211214. The AppDMClient binary file, which is used during the firmware installation process, can be modified by an attacker to bypass the digital signature check of AppUpgrade and .lge.upgrade.xml files, which are used during the firmware installation process. This indirectly allows an attacker to use a custom version of AppUpgrade and .lge.upgrade.xml files.