ESF-IDF is the Espressif Internet of Things (IOT) Development Framework. In versions 5.5.1, 5.4.3, 5.3.4, 5.2.6, 5.1.6, and earlier, in the avrcvendormsg() function of the ESP-IDF BlueDroid AVRCP stack, the allocated buffer size was validated using AVRCMINCMDLEN (20 bytes). However, the actual fixed header data written before the vendor payload exceeds this value. This totals 29 bytes written before pmsg->pvendordata is copied. Using the old AVRCMINCMDLEN could allow an out-of-bounds write if vendorlen approaches the buffer limit. For commands where vendorlen is large, the original buffer allocation may be insufficient, causing writes beyond the allocated memory. This can lead to memory corruption, crashes, or other undefined behavior. The overflow could be larger when assertions are disabled.