CVE-2025-40755 Overview
CVE-2025-40755 is a SQL injection vulnerability in Siemens SINEC NMS (Network Management System) affecting all versions prior to V4.0 SP1. The flaw resides in the getTotalAndFilterCounts endpoint, where user-supplied input is concatenated into SQL queries without proper sanitization [CWE-89]. An authenticated low-privileged attacker can inject malicious SQL statements to modify database contents and escalate privileges within the application. The issue was reported through the Zero Day Initiative as ZDI-CAN-26570 and addressed in Siemens advisory SSA-318832.
Critical Impact
Authenticated attackers with low privileges can inject SQL statements through the getTotalAndFilterCounts endpoint, insert arbitrary data, and escalate to higher privileges in the SINEC NMS management platform.
Affected Products
- Siemens SINEC NMS (all versions before V4.0 SP1)
- Siemens SINEC NMS V4.0
- Industrial network management deployments running vulnerable SINEC NMS builds
Discovery Timeline
- 2025-10-14 - CVE-2025-40755 published to NVD
- 2025-10-21 - Last updated in NVD database
Technical Details for CVE-2025-40755
Vulnerability Analysis
SINEC NMS is Siemens' centralized network management platform used to monitor and configure industrial network devices. The vulnerable getTotalAndFilterCounts endpoint accepts filter parameters from authenticated users and incorporates them into SQL statements executed against the backend database. Because the endpoint fails to parameterize or validate these inputs, an attacker can append additional SQL clauses to alter query semantics. Successful exploitation allows the attacker to insert rows into privileged tables, leading to privilege escalation within the application's authorization model.
The vulnerability is reachable over the network and requires only low-privileged authenticated access. No user interaction is necessary, and attack complexity is low. Impacts to confidentiality, integrity, and availability of the SINEC NMS database are all rated high.
Root Cause
The root cause is improper neutralization of special elements used in an SQL command [CWE-89]. The getTotalAndFilterCounts handler builds dynamic SQL using attacker-controlled filter values rather than using prepared statements or strict allow-list validation. This permits injected SQL fragments to be parsed and executed by the database engine.
Attack Vector
An attacker first obtains valid low-privileged credentials to the SINEC NMS web interface, then issues crafted HTTP requests to the getTotalAndFilterCounts endpoint. By embedding SQL syntax inside filter parameters, the attacker can extend the original query with UNION, INSERT, or stacked statements. Inserting records into tables that govern roles or permissions grants the attacker elevated access without requiring administrative credentials at the time of attack.
No public proof-of-concept code is currently available. Refer to the Siemens Security Advisory SSA-318832 for vendor technical details.
Detection Methods for CVE-2025-40755
Indicators of Compromise
- HTTP requests to the getTotalAndFilterCounts endpoint containing SQL syntax such as UNION, SELECT, INSERT, single quotes, or comment sequences (--, /*) in filter parameters.
- Unexpected new entries in SINEC NMS user, role, or permission tables that do not correspond to administrator activity.
- Authenticated sessions from low-privileged accounts followed by actions normally restricted to administrators.
Detection Strategies
- Inspect SINEC NMS web server and application logs for anomalous query strings or POST bodies targeting getTotalAndFilterCounts.
- Enable database audit logging to capture unusual INSERT or UPDATE statements against authorization-related tables.
- Correlate authentication events with privilege changes to identify accounts that gained roles outside normal administrative workflows.
Monitoring Recommendations
- Deploy a web application firewall in front of SINEC NMS with SQL injection signatures tuned for the management endpoints.
- Forward SINEC NMS application, database, and authentication logs to a centralized analytics platform for correlation and retention.
- Establish baselines for legitimate filter parameter values and alert on deviations or encoded payloads.
How to Mitigate CVE-2025-40755
Immediate Actions Required
- Upgrade SINEC NMS to V4.0 SP1 or later as published in Siemens Security Advisory SSA-318832.
- Restrict access to the SINEC NMS web interface to trusted management networks and operator workstations only.
- Review and remove unnecessary low-privileged accounts, and rotate credentials for any account that may have been exposed.
- Audit SINEC NMS user, role, and permission tables for unauthorized entries created prior to patching.
Patch Information
Siemens has released SINEC NMS V4.0 SP1, which remediates the SQL injection in the getTotalAndFilterCounts endpoint. Administrators should follow the upgrade procedure documented in advisory SSA-318832 and verify the installed version after upgrade. All versions prior to V4.0 SP1 remain vulnerable and must be updated.
Workarounds
- Limit network reachability of SINEC NMS using firewall rules and segmentation aligned with Siemens operational guidelines for industrial security.
- Enforce least-privilege access and disable unused accounts to reduce the population of identities that can reach the vulnerable endpoint.
- Monitor SINEC NMS access and database activity continuously until the patch is applied across all instances.
# Example firewall rule restricting SINEC NMS access to a management subnet
iptables -A INPUT -p tcp --dport 443 -s 10.10.20.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
