CVE-2025-56234 Denial of service in n/a
Attackers can disrupt normal connections on Nanda Automation Technology PLCs by sending random TCP RST packets due to improper sequence number validation.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2025-56234?
CVE-2025-56234 is a high-severity denial of service vulnerability in n/a, published on 29 Sep 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Weakness: CWE-400
Which versions are affected by CVE-2025-56234?
How do I fix CVE-2025-56234?
No fix has been published for CVE-2025-56234 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2025-56234 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-56234 exists.
Sources
Also known as GHSA-wx6w-7qw9-7qj5.