static char *plist_utf16_to_utf8(uint16_t *unistr, long len, long *items_read, long *items_written)
{
	if (!unistr || (len <= 0)) return NULL;
	char *outbuf = (char*)malloc(4*(len+1));
	int p = 0;
	long i = 0;

	uint16_t wc;
	uint32_t w;
	int read_lead_surrogate = 0; 

	while (i < len) {
		wc = unistr[i++];
		if (wc >= 0xD800 && wc <= 0xDBFF) {
			if (!read_lead_surrogate) {
				read_lead_surrogate = 1;
				w = 0x010000 + ((wc & 0x3FF) << 10);
			} else {
				read_lead_surrogate = 0;
			}
		} else if (wc >= 0xDC00 && wc <= 0xDFFF) {
			if (read_lead_surrogate) {
				read_lead_surrogate = 0;
				w = w | (wc & 0x3FF);
				outbuf[p++] = (char)(0xF0 + ((w >> 18) & 0x7));
				outbuf[p++] = (char)(0x80 + ((w >> 12) & 0x3F));
				outbuf[p++] = (char)(0x80 + ((w >> 6) & 0x3F));
				outbuf[p++] = (char)(0x80 + (w & 0x3F));
			} else {
			}
		} else if (wc >= 0x800) {
			outbuf[p++] = (char)(0xE0 + ((wc >> 12) & 0xF));
			outbuf[p++] = (char)(0x80 + ((wc >> 6) & 0x3F));
			outbuf[p++] = (char)(0x80 + (wc & 0x3F));
		} else if (wc >= 0x80) {
			outbuf[p++] = (char)(0xC0 + ((wc >> 6) & 0x1F));
			outbuf[p++] = (char)(0x80 + (wc & 0x3F));
		} else {
			outbuf[p++] = (char)(wc & 0x7F);
		}
	}
	if (items_read) {
		*items_read = i;
	}
	if (items_written) {
		*items_written = p;
	}
	outbuf[p] = 0;

	return outbuf;
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.