CVE-2025-7746: XSS in Schneider Electric Altivar Drives—Fixes & Mitigations

A newly disclosed Cross‑Site Scripting (XSS) vulnerability, tracked as CVE‑2025‑7746, affects a broad set of Schneider Electric Altivar drives and modules — including the ATVdPAC module (fixed in VW3A3530D version 25.0), multiple Altivar Process and Machine drives, and the ILC992 InterLink Converter — and requires immediate attention from both OT operators and IT teams that manage networks where these devices reside. (nvd.nist.gov) (tenable.com)

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Background​

Industrial drives and embedded controllers in the Schneider Electric Altivar family are widely deployed across manufacturing, energy and process industries. These devices often include web management interfaces for configuration and diagnostics — convenient for engineers, but also a frequent attack surface when input sanitization is incomplete.
The vulnerability is categorized under CWE‑79: Improper Neutralization of Input During Web Page Generation ('Cross‑site Scripting'). In practical terms, an XSS flaw allows an attacker to inject script content into web pages served by the device. If a user with access to the device’s web UI visits a maliciously crafted page, an attacker can run script in that user’s browser context and potentially read or manipulate session data, configuration values, or other content presented in the browser. The CVSS v4 base score published for this CVE is 5.3 (Medium), with vectors indicating network exploitability and requiring user interaction in many attack paths. (nvd.nist.gov) (tenable.com)
The issue was disclosed through coordinated vendor advisories and included in industry advisories republished by government CERTs. The vendor advisory references and machine‑readable CSAF data packages list the affected models and provide remediation guidance; those advisories are the authoritative starting point for operators.

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Overview of Affected Products​

Schneider Electric’s advisory lists a wide range of Altivar models and related modules as impacted. The most notable items on the vendor’s list include:

• ATVdPAC module (VW3A3530D): Versions prior to 25.0. Version 25.0 is the vendor‑delivered fix for the module.
• Altivar Process Drives: ATV930, ATV950, ATV955, ATV960, ATV980, ATV9A0, ATV9B0, ATV9L0, ATV991, ATV992, ATV993 — listed as affected (all versions).
• Altivar Process Drives – ATV6xx series: ATV630, ATV650, ATV660, ATV680, ATV6A0, ATV6B0, ATV6L0 — listed as affected (all versions).
• Altivar Machine Drives: ATV340E (all versions).
• ATV6000 Medium Voltage and ATS490 Altivar Soft Starter (all versions).
• Communication modules: VW3A3720, VW3A3721 and ILC992 InterLink Converter — all versions listed as affected.

This is a broad hit list that covers devices embedded across many OT environments; operators should treat any of the listed models as potentially vulnerable until validated otherwise. The National Vulnerability Database (NVD) entry and multiple vulnerability trackers echo the vendor list and scoring. (nvd.nist.gov) (tenable.com)

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Technical details and exploitation risk​

What the vulnerability is​

• The root cause is improper neutralization of user‑supplied input in parts of the device web front end. In such cases, unescaped input can be reflected into web pages and interpreted by a victim’s browser as executable script.
• Typical outcomes of an XSS successful exploitation include theft of authentication cookies or session tokens, DOM‑based manipulation of the displayed content, and browser‑initiated actions that the user appears to have performed.

Attack vector and difficulty​

• The published CVSS v4 vector indicates network‑accessible attack surface with low attack complexity, but requires user interaction (e.g., a logged‑in engineer clicking a malicious link). That aligns with a reflected or stored XSS scenario in which an attacker-hosted payload becomes relevant when a legitimate user loads a page. (nvd.nist.gov)
• There are no confirmed reports of active exploitation in the wild at the time of this writing, but the vulnerability's network accessibility and low complexity make it a realistic target for opportunistic attackers. Operators should assume active exploitation is possible and act accordingly. (tenable.com)

Impact specifics for OT environments​

• An attacker who successfully leverages XSS in an Altivar web UI could:
• Read or modify values visible through the browser-based management UI.
• Phish credentials by displaying fake pages or invisibly capturing input.
• Pivot laterally if the captured credentials or session tokens are reused across management systems.
• Cause safe/unsafe configuration changes if the UI exposes critical parameters (note: actual device safety implications depend on product and configuration; this must be assessed per site).

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Vendor fixes and mitigations​

Schneider Electric’s published guidance — including a CSAF package and a Security Notification — confirms that:

• ATVdPAC module: VW3A3530D version 25.0 includes a code change that addresses CVE‑2025‑7746 and is available from Schneider Electric’s Customer Care Center; operators running earlier versions should obtain and install 25.0 as the primary fix. (se.com)
• For the large set of other listed devices, Schneider Electric is establishing a remediation plan and working to include fixes in future firmware releases. Until fixed firmware is available, Schneider’s recommended compensating mitigations are:
• Deactivate the built‑in webserver when the interface is not required.
• Segment networks to isolate OT devices from corporate networks and the Internet.
• Block or restrict access to port 80/HTTP (and other management ports) via firewall rules and ACLs.
• Use secure remote access (VPN tunnels) for necessary remote connections — and ensure VPN appliances and endpoints are fully patched.
• Harden engineering workstations and raise end‑user cybersecurity awareness to reduce the likelihood of successful social‑engineering exploits.

Government CERT guidance (for example, CISA advisories on Schneider products more broadly) reiterates the standard defensive posture: minimize external exposure, place ICS devices behind firewalls, and limit remote access to vetted, secure channels. Those recommendations hold here as well. (cisa.gov)

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Practical steps for teams (prioritized)​

Operators should treat this as an operational urgency. The following sequence helps organizations balance safety, availability and security.

• Inventory and triage
• Identify all instances of the affected models (match serial numbers, firmware build numbers, module part numbers such as VW3A3530D).
• Prioritize devices accessible to corporate or remote networks and those whose management interfaces are exposed beyond isolated OT subnets.
• Immediate compensating controls
• If the webserver is not required, disable it now.
• Block inbound access to HTTP/port 80 (or any management ports used by the device) at the perimeter and between IT/OT segments.
• Enforce strict ACLs on switches and firewalls to limit access to specific engineering workstation IPs.
• Patch management and change control
• For ATVdPAC: obtain and validate VW3A3530D v25.0 from Schneider Electric Customer Care and schedule deployment through your change control process. Test on a lab or offline system first.
• For other models: monitor Schneider Electric advisories for firmware releases and apply vendor patches as they become available.
• Secure remote access and monitoring
• Use secure VPNs with multi‑factor authentication and restrict the VPN to OT‑only resources.
• Add host and network detections — e.g., webshell attempts, anomalous HTTP requests, unusual user interactions in management UIs.
• Increase monitoring for suspicious activity and correlate logs from engineering workstations, VPN gateways and the drives’ management interfaces.
• User education
• Brief engineers about the danger of clicking unknown links while logged into drive management UIs.
• Treat management workstations with the same controls as servers — apply endpoint protection, hardening and software update discipline.

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Detection strategies and hunting tips​

• Look for unexpected HTTP GET/POST parameters containing script tags or URL‑encoded payloads heading to device interfaces.
• Check webserver logs (if accessible) on drives and gateway devices for unusual query strings or repeated attempts to inject payloads.
• On engineering workstations, hunt for outbound connections to unknown domains concurrent with drive‑management sessions — this may indicate exfiltration or C2 staging triggered by an XSS payload.
• Correlate timestamps between VPN sessions, login times, management UI requests and configuration changes to identify suspicious sequences.

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Why this matters: operational and supply‑chain context​

• These devices sit at the boundary between the physical process and network management. Any compromise that allows attackers to manipulate configuration or glean credentials can threaten operational continuity.
• The advisory covers devices used globally across critical manufacturing and process sectors; the potential impact scales with deployment density and the degree of network exposure. Government advisories emphasize that minimizing Internet exposure for control system devices is essential. (cisa.gov)

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Critical assessment: strengths and risks of the vendor response​

Notable strengths​

• Vendor acknowledgement and CSAF packaging: Schneider Electric produced a Security Notification and a machine‑readable CSAF document describing the issue and listing affected models — useful for automated ingestion and triage. This is an important operational improvement for large integrators who rely on automated vulnerability feeds.
• Immediate fix for ATVdPAC: Providing a fixed build (VW3A3530D v25.0) for the ATVdPAC module demonstrates the vendor prioritized at least one tangible remediation path that operators can apply now. (se.com)

Ongoing risks and weaknesses​

• Wide product scope with delayed firmware: The advisory lists many models with no immediate firmware available and only a planned remediation. That leaves a long tail of vulnerable devices that must rely on compensating controls, which are inevitably human‑dependent and error prone.
• User‑interaction requirement can lull teams into complacency: Because the CVSS and vendor notes indicate user interaction is required, there’s a risk that some operators under‑prioritize remediation — yet engineering staff routinely browse management interfaces, meaning that the practical attack surface is large.
• Web UI vulnerabilities in OT devices remain a systemic weakness: This advisory reinforces a recurring pattern: convenience features (web‑based management, discovery services) increase attack surface. Long‑term, vendors and integrators must prioritize secure defaults: disabled web interfaces unless explicitly enabled, strict CSP/encoding, and role‑based access enforced at the device layer.

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For Windows and IT teams: coordination checklist​

• Treat these OT devices as high‑value assets in your enterprise asset inventory.
• Coordinate with OT engineers to implement firewall rules that only allow management traffic from a small set of hardened, patched engineering workstations.
• Ensure endpoint protection, web filters, and email security are configured to reduce social‑engineering risks that could deliver XSS payload URLs to engineers.
• If remote access is required, use tightly controlled jump hosts that are monitored and restricted to OT‑specific sessions only.

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Verification and cross‑checks​

Key claims in this article are corroborated by the NVD entry for CVE‑2025‑7746 and multiple vulnerability trackers that mirror the vendor advisory; the NVD shows the CWE‑79 classification and the CNA‑provided CVSS v4 vector, while Tenable and other databases reproduce the vendor scoring and affected product list. Operators should consult the vendor bulletin (SEVD) and official CSAF JSON for authoritative guidance and to validate the exact firmware builds and remediation timelines for their model numbers. (nvd.nist.gov) (tenable.com)
Caution: the NVD entry indicates the record is pending NVD enrichment and contains CNA‑supplied scoring; where the vendor‑provided documentation conflicts with third‑party trackers, prioritize Schneider Electric’s SEVD advisory until further confirmation. (nvd.nist.gov)

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Checklist for a secure remediation rollout (recommended sequence)​

• Assemble the cross‑functional team: OT engineers, IT/network, cybersecurity, and change control.
• Inventory all affected devices and identify which have publicly exposed or network‑accessible web interfaces.
• Apply emergency compensating controls (disable web UI; firewall/ACLs).
• Test vendor patch (where available) in a lab and then schedule production deployment through change control.
• Monitor logs and hunt for indicators of compromise for a minimum of 90 days post‑deployment.
• Review vendor notifications regularly and subscribe to Schneider Electric’s security notification feed for follow‑ups and future firmware releases.

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Final analysis and outlook​

This vulnerability is emblematic of the persistent tension in industrial automation between usability and security. The immediate availability of a fixed build for the ATVdPAC module (VW3A3530D v25.0) is positive, but the broad list of devices still awaiting remediation means the operational community must rely on network controls and human processes in the near term.
The technical severity (XSS) is not novel, but the context — network‑accessible management interfaces on devices controlling physical processes — elevates the operational risk. Because many industrial environments use shared engineering workstations and cross‑linked management systems, a browser‑based compromise can have outsized effects if credentials or tokens are exposed.
Actionable priorities for every impacted organization right now:

• Treat the advisory as an operational security incident: inventory, isolate, mitigate, and patch as vendor builds become available.
• Harden remote access and engineering workstations immediately.
• Assume an attacker could target these devices opportunistically and monitor accordingly.

The responsible path forward pairs vendor patching with stronger network architecture and endpoint discipline. That combined approach reduces the window of exposure and raises the bar for attackers who would exploit browser‑based vulnerabilities in production OT environments. (se.com) (cisa.gov)

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Conclusion
CVE‑2025‑7746 is a medium‑scored but practically significant vulnerability because it targets web management functionality on devices that sit inside industrial control networks. Organizations operating affected Schneider Electric Altivar drives and modules should immediately inventory affected assets, apply Schneider’s available fix for the ATVdPAC module where appropriate, implement the vendor and CISA compensating controls, and prepare to deploy vendor firmware updates for the remaining models as they are released. Prompt, coordinated action across OT and IT teams will minimize operational risk while maintaining availability and safety. (nvd.nist.gov) (tenable.com)

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Source: CISA Schneider Electric Altivar Products, ATVdPAC Module, ILC992 InterLink Converter | CISA