CVE-2021-40368 Denial of service in SIMATIC S7-400 CPU 412-1 DP V7
An attacker can cause a denial-of-service condition on Siemens SIMATIC S7-400 PLCs by sending specially crafted packets to port 102/tcp.
- 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-2021-40368?
CVE-2021-40368 is a high-severity denial of service vulnerability in Siemens SIMATIC S7-400 CPU 412-1 DP V7, published on 12 Apr 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A vulnerability has been identified in SIMATIC S7-400 CPU 412-1 DP V7 (All versions), SIMATIC S7-400 CPU 412-2 DP V7 (All versions), SIMATIC S7-400 CPU 412-2 PN/DP V7 (All versions < V7.0.3), SIMATIC S7-400 CPU 414-2 DP V7 (All versions), SIMATIC S7-400 CPU 414-3 DP V7 (All versions), SIMATIC S7-400 CPU 414-3 PN/DP V7 (All versions < V7.0.3), SIMATIC S7-400 CPU 414F-3 PN/DP V7 (All versions < V7.0.3), SIMATIC S7-400 CPU 416-2 DP V7 (All versions), SIMATIC S7-400 CPU 416-3 DP V7 (All versions), SIMATIC S7-400 CPU 416-3 PN/DP V7 (All versions < V7.0.3), SIMATIC S7-400 CPU 416F-2 DP V7 (All versions), SIMATIC S7-400 CPU 416F-3 PN/DP V7 (All versions < V7.0.3), SIMATIC S7-400 CPU 417-4 DP V7 (All versions), SIMATIC S7-400 H V6 CPU family (incl. SIPLUS variants) (All versions < V6.0.10), SIMATIC S7-410 V10 CPU family (incl. SIPLUS variants) (All versions < V10.1), SIMATIC S7-410 V8 CPU family (incl. SIPLUS variants) (All versions < V8.2.3), SIPLUS S7-400 CPU 414-3 PN/DP V7 (All versions < V7.0.3), SIPLUS S7-400 CPU 416-3 PN/DP V7 (All versions < V7.0.3), SIPLUS S7-400 CPU 416-3 V7 (All versions), SIPLUS S7-400 CPU 417-4 V7 (All versions). Affected devices improperly handle specially crafted packets sent to port 102/tcp.
This could allow an attacker to create a Denial-of-Service condition. A restart is needed to restore normal operations.
Weakness: CWE-119
Which versions are affected by CVE-2021-40368?
It affects 4 products.
Products include Siemens Simatic S7-400 Pn\/Dp V7 Firmware, Siemens Simatic S7-400h V6 Firmware, Siemens Simatic S7-410 V10 Firmware, Siemens Simatic S7-410 V8 Firmware.
How do I fix CVE-2021-40368?
No fix has been published for CVE-2021-40368 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-2021-40368 being exploited?
There is no known exploitation of CVE-2021-40368 in the wild and no public exploit code.
Sources
Also known as GHSA-q4w8-vrmx-g9m6.