Cross-Site Request Forgery (CSRF) vulnerability in the OAuth implementation of the Tuya SDK 6.5.0 for Android and iOS, affects the Tuya Smart and Smartlife mobile applications, as well as other third-party applications that integrate the SDK, allows an attacker to link their own Amazon Alexa account to a victim's Tuya account. The applications fail to validate the OAuth state parameter during the account linking flow, enabling a cross-site request forgery (CSRF)-like attack. By tricking the victim into clicking a crafted authorization link, an attacker can complete the OAuth flow on the victim's behalf, resulting in unauthorized Alexa access to the victim's Tuya-connected devices. This affects users regardless of prior Alexa linkage and does not require the Tuya application to be active at the time. Successful exploitation may allow remote control of devices such as cameras, doorbells, door locks, or alarms.