8.3
HIGH
CVE-2025-40743
Siemens SINUMERIK VNC Authentication Bypass
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.

INFO

Published Date :

Aug. 12, 2025, 12:15 p.m.

Last Modified :

Aug. 12, 2025, 2:25 p.m.

Remotely Exploitable :

No

Impact Score :

5.5

Exploitability Score :

2.8
Public PoC/Exploit Available at Github

CVE-2025-40743 has a 1 public PoC/Exploit available at Github. Go to the Public Exploits tab to see the list.

Affected Products

The following products are affected by CVE-2025-40743 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2025-40743.

URL Resource
https://cert-portal.siemens.com/productcert/html/ssa-177847.html

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Community reconstruction of the legacy JSON NVD Data Feeds. This project uses and redistributes data from the NVD API but is neither endorsed nor certified by the NVD.

Shell

Updated: 6 hours, 53 minutes ago
171 stars 24 fork 24 watcher
Born at : May 17, 2023, 8 a.m. This repo has been linked 53 different CVEs too.

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2025-40743 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2025-40743 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Aug. 12, 2025

    Action Type Old Value New Value
    Added 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.
    Added CVSS V4.0 AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CVSS V3.1 AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L
    Added CWE CWE-288
    Added Reference https://cert-portal.siemens.com/productcert/html/ssa-177847.html
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2025-40743 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2025-40743 weaknesses.

CVSS31 - Vulnerability Scoring System
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability