DescriptionXWEB EVO 4.3.0 through 5.8.8 contains an unauthenticated arbitrary file write vulnerability that allows remote attackers to modify the system configuration file /etc/xwebconfig.json by sending a crafted POST request to config.lua with action=set, which performs no session validation and writes the raw, unvalidated request body. Attackers can tamper with configuration values such as model and plugin fields or trigger a SYSTEM_NOT_CONFIGURED state via the unauthenticated action=get and action=set operations, resulting in configuration tampering and denial of service. This product line reached it's end of service date in March 2026.