Vulnerability in Siemens Sinumerik 828d Ppu.4

CVE-2025-40743

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.

EPSS: 0.002 (15.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.3 (High). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-40743?
CVE-2025-40743 is a high-severity vulnerability in Siemens Sinumerik 828d Ppu.4, classified under Authentication Bypass Using an Alternate Path or Channel. CVSS score: 8.3/10. Published 2025-08-12.
How severe is CVE-2025-40743?
High severity. CVSS v3 base score is 8.3 out of 10.