【中文导读】该 CVE 涉及安全缺陷（高危风险）。具体受影响产品、版本和修复方案以 NVD/厂商公告为准。 【原始描述】AT_NA2000 from Nanda Automation Technology vendor has a denial-of-service vulnerability. For the processing of TCP RST packets, PLC AT_NA2000 has a wide acceptable range of sequence numbers. It does not require the sequence number to exactly match the next expected sequence value, just to be within the current receive window, which violates RFC5961. This flaw allows attackers to send multiple random TCP RST packets to hit the acceptable range of sequence numbers, thereby interrupting normal connections and causing a denial-of-service attack.