Tasmota through 16.0.0, fixed in commit e97e1e4, contains a heap out-of-bounds write vulnerability in SendReceiveDeviceGroupMessage() that allows unauthenticated attackers on the local network to corrupt heap memory by sending crafted Device Groups messages over UDP port 4447 that cause the logremaining counter to go negative and writes to exceed the fixed 512-byte buffer. Attackers can exploit this flaw to crash the device or potentially achieve native code execution on ESP8266 and ESP32 platforms that lack ASLR and heap cookies.

Tasmota through 16.0.0, fixed in commit 1cb7ebc, contains a cross-site request forgery vulnerability that allows unauthenticated attackers to bypass Referer-based CSRF protection in HttpCheckPriviledgedAccess() by crafting a Referer header where the device hostname or IP appears as a substring immediately after http://.evil.com/. Attackers can lure an administrator on the device's network to a malicious page to issue arbitrary console commands and reconfigure Wi-Fi, MQTT, settings, or firmware on devices lacking a WebPassword.

An issue in fetchjpg() in xdrv10scripter.ino in Tasmota through 15.3.0.3 allows a remote attacker to cause heap buffer overflow. The Content-Length from a JPEG stream is stored in a uint16t variable; values above 65535 wrap around, causing allocation of a smaller buffer than the data actually read.