CVE-2025-20352: Stratix SNMP Overflow Threat to Industrial Switches

Rockwell Automation’s Stratix line of industrial switches is in the crosshairs after a stack-based buffer overflow in the SNMP subsystem of embedded Cisco IOS XE was assigned CVE‑2025‑20352, creating a remote, low-complexity attack path that can cause denial-of-service and — with elevated privileges — full root-level code execution on affected devices. This vulnerability affects multiple Stratix families and shipped firmware builds, and while Rockwell has begun coordinating fixes with Cisco and CISA, operators must treat every Stratix device with SNMP enabled as high-priority for inventory, isolation, and remediation until confirmed patched.

Background / Overview​

Industrial switches such as the Stratix series often run embedded networking stacks derived from mainstream networking vendors. In this case, the affected Stratix devices include Stratix 5700, 5400, 5410, 5200 and 5800 models running certain Stratix IOS and firmware builds that incorporate Cisco IOS XE code. The exploitable defect is a stack overflow in the SNMP subsystem that can be triggered by crafted SNMP packets over IPv4 or IPv6 when the attacker possesses SNMP credentials or community strings. The vulnerability was cataloged as CVE‑2025‑20352 and has been publicly disclosed through coordinated vendor and government advisories.
Rockwell’s advisory lists the specific affected firmware lines and the vendor’s expected remediation timelines: Stratix 5700 / 5400 / 5410 builds up to v15.2(8)E7 are in-scope (fix expected October 2025), and Stratix 5200 / 5800 builds up to v17.17.01 are listed as impacted with fixes expected in March 2026. Operators should treat those expected dates as vendor guidance that may change as testing and distribution complete.

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What the vulnerability is (technical summary)​

• Vulnerability class: Stack-based buffer overflow in the SNMP subsystem present in Cisco IOS / IOS XE code integrated into Stratix firmware.
• CVE: CVE‑2025‑20352.
• Attack vector: Network (IPv4/IPv6) via SNMP protocol.
• Privilege requirements: Attacker must possess SNMP credentials — SNMPv1/v2c read-only community string (for some impacts) or SNMPv3 user credentials; root-level code execution requires administrative or privilege‑15 device credentials in combination with SNMP credentials.
• Impact: Denial-of-Service (device reload or SNMP daemon crash) for low‑privileged authenticated actors; potential arbitrary code execution as root for highly privileged authenticated actors on affected Cisco IOS XE builds embedded in Stratix devices.
• Exploit mechanism: Crafted SNMP packet triggers stack overflow in parser/handler code path. The overflow can be weaponized to corrupt return frames or function pointers in memory on architectures that lack exploit mitigations, enabling code execution paths or forcing process/device restarts.

These are not theoretical concerns: multiple security organizations and network-scanning intelligence providers observed both widespread exposure of SNMP services and reports of in-the-wild exploitation tied to the underlying Cisco IOS/IOS XE flaw. Public reporting as of late September 2025 indicates active exploitation of the same SNMP family of vulnerabilities affecting IOS and IOS XE.

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Affected products and exact versioning​

Rockwell’s advisory identifies the following primary Stratix product/version boundaries:

• Stratix 5700 / 5400 / 5410: Stratix IOS versions v15.2(8)E7 and prior. Fix expected in October 2025.
• Stratix 5200 / 5800: Firmware/IOS v17.17.01 and prior. Fix expected in March 2026.

Operators must take care to verify the exact build string on each device (including FRN/revision and full image identifier) — device labels such as “15.2(8)E7” can sometimes appear in multiple variant suffixes that matter for patch applicability. Do not rely solely on model name; confirm the installed Stratix IOS/firmware build on each switch before applying or planning a patch.

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How bad is it? Risk evaluation and scoring​

The Common Vulnerability Scoring System values associated with this defect reflect serious operational risk:

• CVSS v3 (public reporting): 7.7 (High) — reflects network attack vector, low attack complexity for authenticated SNMP access, and high availability impact (DoS); in some Cisco advisory variants the integrity/availability scope is set to Changed.
• CVSS v4 (vendor / republished advisory): 6.3 (per republished vectoring) — modernized scoring under CVSS v4 that includes attack requirements and victim outcomes; values can differ from v3 for the same technical facts. Note that CVSS is a prioritization aid — real-world impact for OT depends on device placement and function.

Operational impact in manufacturing and critical infrastructure should be treated as very high because switches do more than forward packets: they host management planes, enforce segmentation (VLANs, ACLs), and can be manipulated to change network topology or access paths in ways that directly affect PLCs, HMIs, and other safety-critical elements. A compromised Stratix can thus enable lateral movement into OT segments or cause production outages lasting hours or days.

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What changed since the initial disclosure​

Initial government advisories often include language like “no known public exploitation at time of publication.” That can be accurate at a given timestamp but changes quickly. After the vulnerability was cataloged, multiple independent sources — including Cisco’s own PSIRT advisory and third-party telemetry providers — reported active exploitation in the wild tied to this SNMP family of issues. Treat any “no known exploitation” statements as temporal: if your devices were internet-reachable or reachable from misconfigured corporate networks at any time since the vulnerability window opened, assume risk and validate logs and patch status.

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Strengths and limitations of the public information​

Strengths:

• Vendor advisories (Rockwell, Cisco) provide the authoritative affected-product mapping, suggested fixed-version rollouts, and technical context needed to triage asset inventories.
• Centralized vulnerability records (NVD) summarize exploit mechanics and scoring, useful for automated vulnerability management systems.
• Independent security researchers and scanning vendors provide exposure counts and behavioral telemetry that help prioritize which devices to cut off from the network immediately.

Limitations / risks:

• Vendor "expected" fix dates can shift. Rockwell’s published expected fix months (October 2025 / March 2026) should be treated as schedules, not guarantees; coordinate with vendor support for exact FRNs when they are available.
• The advisories intentionally do not publish full exploit code; that is a security design choice, but it also means security teams must assume worst-case post-exploit outcomes and design compensations accordingly.
• Attack specifics can vary by model and installed feature set. Some Stratix models may be able to be fully owned by a successful exploit; in others the immediate outcome may be limited to DoS or configuration manipulations. Validate behavior in a lab when possible.

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Immediate, prioritized remediation checklist (practical steps)​

• Inventory: Immediately identify every Stratix device model and installed image/FRN in your environment. Export device show/version outputs and record serial numbers and FRN labels. This enables targeted patching and rollback planning.
• Isolate: If any affected device is reachable from the internet or a poorly segmented corporate network, remove it from external routable access and place it behind strict firewall rules. Minimize network exposure until patches are confirmed.
• Restrict SNMP: Restrict SNMP access to a limited set of management IPs (management jump hosts). For SNMPv2c, change all community strings, and where possible replace v1/v2c use with properly configured SNMPv3 with strong credentials and restricted views. Note: SNMP restrictions are mitigating controls and do not replace vendor patches.
• Apply Patches: Install the vendor-supplied firmware/IOS updates as soon as Rockwell releases confirmed corrected FRNs for your device models, or apply Cisco IOS XE patches where applicable. Test upgrades in a staging environment before mass deployment to avoid unintended service disruption.
• Harden Management Plane: Enforce least-privilege for device administrative accounts (no shared admin credentials, use TACACS+/RADIUS, enable role-based accounts) and rotate all management credentials. Disable unused services on Stratix devices.
• Monitor: Enable and centralize syslog and configuration-change auditing. Alert on unexpected reboots, SNMP session anomalies, and unplanned config pushes. Maintain baselined config hashes and detect divergence quickly.
• Forensics if suspected compromise: Preserve device RAM/volatile data where possible; capture running configuration and logs before rebooting; isolate and coordinate with Rockwell and CISA if evidence of exploitation is observed.

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Detection and monitoring guidance (concrete checks)​

• Watch for unexpected device reboots or SNMP daemon restarts. Anomalous reloads on network switches are a red flag.
• Alert on configuration changes originating from unexpected sources (non-jump-host IPs), especially ACL, VLAN, and routing modifications.
• Create IDS/IPS rules to flag unusual SNMP PDUs and oversized or malformed SNMP messages. While SNMP traffic is legitimate in controls networks, anomalies in size, OID targets, or traffic timing are suspicious.
• Audit SNMP community strings and SNMPv3 user lists across devices. Any community string discovered in a network scan should be treated as compromised until proven otherwise.
• Correlate jump-host process and EDR logs for unusual usage patterns or evidence of credential theft; remote configuration pushes coming from compromised engineering workstations are a common lateral technique.

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Operational trade-offs and recommended patch strategy​

Patching networking equipment in production OT environments requires careful change control. These devices often sit in the critical path for traffic and have long maintenance windows. Follow this prioritized, staged approach:

• Validate the vendor-supplied fix on a lab device mirroring production configuration. Test routing, VLANs, time sync, and management plane access thoroughly.
• Back up current configurations and obtain a tested rollback plan that includes console access procedures in case the patched device behaves unexpectedly.
• Schedule a staged rollout: patch non-critical, then mid-tier, then critical devices during approved maintenance windows.
• Combine patching with immediate compensations (network ACLs restricting SNMP, management plane lockdown) while waiting for final FRNs on specific Stratix builds.

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Threat modeling: likely attack chains and consequences​

• Scenario A — Opportunistic attacker: A compromised workstation in the corporate network with access to the OT management VLAN uses known SNMP credentials/community strings to send crafted SNMP PDUs that crash or control a Stratix switch, causing production disruption. Outcome: Denial-of-Service, production stoppage, and time-consuming recovery.
• Scenario B — Privileged insider or stolen credentials: An adversary with administrative privilege on the device combines SNMP access with crafted packets to achieve root-level code execution, install persistent backdoors, or modify routing to intercept or manipulate industrial traffic. Outcome: Full device compromise, lateral movement, and persistent manipulation of OT flows.
• Scenario C — Third‑party maintenance abuse: An external vendor with authorized SNMP access inadvertently uploads a crafted configuration or is tricked into applying content that triggers the overflow. Outcome: Unintended attack vector via legitimate support channels.

These scenarios underline why network segmentation, strict vendor remote access policies, and jump-host discipline are essential complements to patching.

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Why this matters for critical manufacturing and ICS operators​

Switches are not “infrastructure furniture” — they are active participants in OT safety and availability. Changes to ACLs, VLANs, routing, or time synchronization can cascade into misrouted PLC messages, loss of telemetry to HMIs, or unsafe states for automated machinery. Given the low complexity of exploitation (provided credentials are present) and the potential for root-level control on some builds, operator risk extends beyond IT confidentiality to physical safety and production continuity. Act accordingly.

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Practical hardening that pays off now (beyond patching)​

• Enforce strict SNMP scoping: bind SNMP to management VLANs, use SNMP views to restrict OID access, and refuse SNMP from any untrusted network.
• Use secure management jump servers with MFA and endpoint posture checks; only these jump servers should be able to reach Stratix management ports.
• Rotate and audit community strings and SNMPv3 keys on a regular cadence; archive rotation records and verify using configuration management tools.
• Detect lateral movement early: instrument east-west traffic, and treat any SNMP scanning activity from internal hosts as high priority.
• Formalize vendor/third-party remote maintenance with ephemeral credentials and session recording. Limit remote sessions to required maintenance windows and log everything.

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Final assessment, unanswered questions, and cautions​

• The technical facts that matter are clear: a stack overflow in the SNMP path of Cisco IOS / IOS XE can be triggered by crafted SNMP messages and — with the right credential context — permit DoS or root-level code execution. Validated advisories from Cisco, Rockwell, and vulnerability registries confirm the core mechanics.
• The public record as of late September 2025 shows both vendor-published patches and independent telemetry indicating exploitation in the wild. Operators must assume real risk and prioritize defenses.
• Some details remain environment-specific: the exact post‑exploit capabilities on a specific Stratix model depend on image build, installed features, and device architecture. Those model-level nuances require lab validation by each owner and confirmation from Rockwell support when patched FRNs are published.
• Rockwell’s public advisory includes expected correction timelines but also warns that customers should implement Cisco workarounds and CISA-recommended best practices until fixed images are applied. This staged, defense‑in‑depth approach is the practical path forward for operational teams.

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Checklist for OT teams (one-page action plan)​

• Immediately identify all Stratix 5700 / 5400 / 5410 / 5200 / 5800 devices and record installed FRN/IOS strings.
• Restrict SNMP access to management jump hosts and disable SNMP where safe.
• Deploy network ACLs to block SNMP from untrusted sources and ensure devices are not internet-exposed.
• Coordinate with Rockwell for confirmed FRNs and schedule staged patching with backups and rollback plans.
• Harden jump hosts and enforce strong admin account controls (TACACS+/RADIUS, MFA).
• Increase logging and alerting for config changes, unexpected reboots, and SNMP anomalies.
• If compromise is suspected, isolate, preserve evidence, and contact vendor/CISA as appropriate.

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This vulnerability is a stark reminder of the supply‑chain nature of modern OT devices: networking stacks written by mainstream vendors can propagate into industrial products and create high-consequence attack paths. For industrial operators, the practical imperative is clear — inventory first, isolate where possible, harden management planes, and apply vendor-supplied fixes promptly and carefully. The combination of low attack complexity (given credentials), potential for device reloads, and the possibility of root-level control in some builds places this vulnerability squarely in the “patch-and-defend-now” category for critical manufacturing and OT environments.

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Source: CISA Rockwell Automation Stratix | CISA