CVE-2025-40743 Auth bypass in SINUMERIK 828D PPU.4
Attackers can bypass VNC authentication to gain unauthorized remote access to SINUMERIK CNC controllers, compromising system confidentiality, integrity, and availability.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2025-40743?
CVE-2025-40743 is a high-severity authentication bypass vulnerability in Siemens SINUMERIK 828D PPU.4, published on 12 Aug 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
A vulnerability has been identified in SINUMERIK 828D PPU.4 (All versions < V4.95 SP5), SINUMERIK 828D PPU.5 (All versions < V5.25 SP1), SINUMERIK 840D sl (All versions < V4.95 SP5), SINUMERIK MC (All versions < V1.25 SP1), SINUMERIK MC V1.15 (All versions < V1.15 SP5), SINUMERIK ONE (All versions < V6.25 SP1), SINUMERIK ONE V6.15 (All versions < V6.15 SP5). The affected application improperly validates authentication for its VNC access service, allowing access with insufficient password verification. This could allow an attacker to gain unauthorized remote access and potentially compromise system confidentiality, integrity, or availability.
Weakness: CWE-288
Which versions are affected by CVE-2025-40743?
How do I fix CVE-2025-40743?
No fix has been published for CVE-2025-40743 yet. Limit exposure of the affected software until one is available.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2025-40743 being exploited?
There is no known exploitation of CVE-2025-40743 in the wild and no public exploit code.
Sources
Also known as GHSA-mr3f-gmg7-3h9c.