int prompt(int flags, pam_handle_t *pamh, int style, char **response,
		const char *fmt, ...)
{
	int r;

	if (PAM_SILENT == (flags & PAM_SILENT)
			&& style != PAM_TEXT_INFO
			&& style != PAM_PROMPT_ECHO_OFF) {
		/* PAM_SILENT does not override the prompting of the user for passwords
		 * etc., it only stops informative messages from being generated. We
		 * use PAM_TEXT_INFO and PAM_PROMPT_ECHO_OFF exclusively for the
		 * password prompt. */
		r = PAM_SUCCESS;
	} else {
		va_list args;
		va_start (args, fmt);
		if (!response) {
			char *p = NULL;
			r = pam_vprompt(pamh, style, &p, fmt, args);
			free(p);
		} else {
			r = pam_vprompt(pamh, style, response, fmt, args);
		}
		va_end(args);
	}

	return r;
}

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.