CVE-2025-20352: Cisco SNMP Buffer Overflow Threat in Rockwell Stratix OT Gear

A recently disclosed stack‑based buffer overflow in Cisco’s SNMP implementation — tracked as CVE‑2025‑20352 — has pulled Rockwell Automation’s Lifecycle Services with Cisco into the security spotlight, forcing industrial operators to reconcile urgent patching requirements, operational continuity constraints, and the systemic risks of third‑party software reuse in OT gear. The flaw can be triggered remotely by crafted SNMP packets and, depending on attacker privileges, can cause denial‑of‑service (DoS) or even enable remote code execution as root on affected IOS XE devices. This combination of exploitable network attack vector and high impact to availability and control-plane integrity elevates the advisory from vendor notice to an operational emergency for organizations that run Stratix, IDC-managed Cisco switching, or Cisco‑managed firewalls inside production environments.

Background​

Rockwell Automation’s Lifecycle Services incorporate Cisco switching and firewall appliances inside Industrial Data Center (IDC) solutions and managed support contracts. Those products reuse Cisco IOS and IOS XE software internally; when Cisco issued its security advisory for CVE‑2025‑20352, Rockwell republished the guidance for impacted Lifecycle Services SKUs and Stratix‑based product families to align remediation recommendations with the upstream vendor fixes. The advisory context is straightforward: this is a third‑party defect (Cisco’s SNMP subsystem) present inside Rockwell‑branded switching and Stratix linecards, not a bespoke Rockwell coding error — but the operational risk is Rockwell’s to help customers manage because these devices run inside production networks.
Why this matters right now

• SNMP remains widely used in production environments for monitoring and management; when SNMP credentials are available to an adversary (or have been compromised), the attack surface opens up.
• Cisco confirmed the vulnerability allows low‑privileged authenticated attackers to cause reloads/DoS and high‑privileged attackers to execute arbitrary code as root on IOS XE devices — outcomes that can translate into lost production, safety incidents, or persistent footholds for lateral movement.
• The National Vulnerability Database and vendor advisories place this CVE in the Known Exploited Vulnerabilities (KEV) context, meaning it carries regulatory urgency for U.S. federal agencies and practical urgency for critical manufacturing operators.

---

Technical overview​

What the flaw is and how it works​

At its core, CVE‑2025‑20352 is a stack‑based buffer overflow inside the SNMP subsystem of Cisco IOS and IOS XE. A crafted SNMP packet can overflow a stack buffer, corrupting control data. With low‑privileged SNMP credentials (e.g., SNMPv2c read‑only), an attacker can trigger conditions that repeatedly reload the device (DoS). With high‑privilege credentials (SNMPv1/v2c or SNMPv3 combined with privilege level 15 or admin credentials), the same overflow can be leveraged for arbitrary code execution as root on IOS XE devices, enabling full system compromise. Exploits can be delivered over IPv4 or IPv6.

Scoring and severity​

• CVE‑2025‑20352 has been scored with a CVSS v3 base of 7.7 (High) in canonical registries, reflecting network attack vector, low complexity, and high availability impact. A CVSS v4 calculation also exists in advisories and tends to reflect similar urgency for defenders.
• The vulnerability is listed in CISA/NVD advisories and was added to the KEV catalog with an associated expedited mitigation timeline for U.S. federal civilian agencies, elevating its treatment in organizational vulnerability-management workflows.

Preconditions for exploitation​

• SNMP must be enabled on the target device.
• The attacker must possess an SNMP community string (SNMPv1/v2c) or valid SNMPv3 credentials; higher rights increase the impact.
• Network reachability to the device (or a pivot into an internal management network) is required.

Exploitation in the wild​

Cisco’s Product Security Incident Response Team (PSIRT) reported observed exploitation following local administrator credential compromises, and multiple CERTs and security vendors reported active in‑the‑wild use shortly after disclosure. That practical evidence — together with widespread SNMP exposure among enterprise switches — means defenders must treat this as more than theoretical risk.

---

Affected products and scope​

Rockwell‑branded impact​

Rockwell’s published advisory identifies Lifecycle Services with Cisco as affected when the embedded software contains the vulnerable Cisco IOS XE builds. Specific Rockwell product lines called out include:

• Industrial Data Center (IDC) with Cisco Switching — Generations 1–5.
• IDC‑Managed and Network‑Managed support contracts using Cisco network switches.
• Firewall‑Managed support contracts where Cisco firewalls are used.

Rockwell published a matrix of Stratix and Stratix‑embedded IOS versions that map to affected Cisco builds and indicated corrected FRNs / IOS builds are available or forthcoming for specific Stratix families. Rockwell also advised managed‑service customers to coordinate remediation directly with Rockwell.

Cisco footprint​

Cisco’s advisory (and independent vulnerability trackers) list a very broad set of IOS and IOS XE releases and families impacted, including widely deployed Catalyst and Meraki switches when running affected code. Cisco recommended immediate upgrades to fixed builds (examples include IOS XE 17.15.4a or later for specific branches) and published mitigation guidance where possible. Because many Stratix devices embed Cisco code, the Stratix lifecycle mirrors Cisco’s fixed‑release cadence.

Exposure estimates​

Third‑party telemetry providers flagged hundreds of thousands of internet‑reachable devices with SNMP exposed — a useful indicator that misconfiguration and internet exposure are common and materially increase attack risk in the wild. Censys reported a significant number of internet‑accessible SNMP services on Cisco gear, underscoring the exposure problem operators must address.

---

Risk evaluation: operational and strategic impacts​

Immediate operational impact​

• Denial of service: Repeated reloads of critical switches and firewalls can sever plant communications, isolate engineering workstations, and cause HMI/SCADA sessions to fail. In automated production, even short outages can trigger safety interlocks, product loss, or regulatory reporting.
• Remote code execution: On IOS XE devices that permit code execution via this flaw, attackers could install backdoors, modify ACLs, exfiltrate configuration backups (including credentials), or manipulate traffic flows — providing a path to persistent network‑level compromise and lateral movement into OT estates.

Attack likelihood and attractiveness​

SNMP is commonly enabled for monitoring, and its credentials are often shared broadly (NMS servers, third‑party contractors, cloud connectors). That credential diffusion, combined with the documented real‑world exploitation, makes the attack attractive for both opportunistic nuisance actors (seeking disruption) and sophisticated actors (seeking persistent access). The inclusion in the KEV catalog further raises the urgency for regulated entities.

Business and safety consequences​

• Production downtime and lost output.
• Safety hazards if control loops or interlocks become unavailable.
• Contractual and regulatory exposure for critical infrastructure providers.
• Increased incident response costs and potential long recovery windows for OT devices that require physical access or staged updates.

---

Mitigation and remediation guidance​

The practical remediation strategy must balance security urgency with operational safety. The vendor and national guidance converge on a layered approach.

Vendor‑level actions​

• Apply the vendor‑provided fixed software builds as soon as feasible. Cisco released patches for affected IOS and IOS XE branches; Rockwell lists corrected Stratix FRNs and indicates corrected downloads (or expected availability dates) for the affected Stratix families within its trust center. Managed‑service customers should coordinate schedule and remediation with Rockwell.
• If a fixed build is not immediately available for a particular Stratix or IDC generation, use vendor guidance for temporary mitigations where applicable and follow Rockwell’s security best practices.

Immediate compensations and tactical steps (Day 0–3)​

• Inventory and prioritize: Identify every device that runs Cisco IOS/IOS XE inside your control and audit whether SNMP is enabled and reachable from untrusted networks. Prioritize outward‑facing and backbone switches serving multiple OT segments.
• Block exposure: Ensure SNMP ports (UDP 161/162) are not reachable from the internet. Apply firewall rules to restrict SNMP access to trusted NMS hosts only. Where possible, apply SNMP access lists or views to restrict OID access to management hosts.
• Rotate and tighten credentials: Replace SNMP community strings and rotate SNMPv3 user credentials; enforce tight access control on who can retrieve/read configuration data. Treat SNMP credentials like any other privileged secret.
• Segmentation: Isolate management networks and place network‑management systems behind jump hosts or bastion servers with strict MFA and logging. Avoid sharing SNMP credentials across business and OT networks.

Longer‑term controls (Week 0–6)​

• Patch windows: Schedule and test vendor fixes in staged environments before production rollout. For Stratix/IDC gear, follow Rockwell’s compatibility guidance and perform program integrity checks after update.
• Detection: Deploy NDR/IDS signatures tuned for malformed SNMP traffic and centralize syslog/telemetry from switches; create alerts for repeated SNMP packets from non‑management hosts.
• Hardening: Move towards SNMPv3 with authenticated and encrypted transport, but recognize that SNMPv3 credentials are sufficient for exploitation if compromised — thus it is not a sole solution. Combine with network isolation and least‑privilege credential practices.

Incident response​

If you observe suspicious SNMP activity or device instability:

• Isolate affected device(s) immediately while preserving logs and configuration backups.
• Do not power‑cycle without capturing volatile state where possible; collect syslogs and packet captures for vendor triage.
• Coordinate with Rockwell support and Cisco PSIRT as needed, and report to incident authorities if you operate in a regulated sector.

---

Practical playbook for Rockwell customers​

• If you have an active Rockwell Infrastructure Managed Service contract: contact Rockwell to schedule remediation and validate that Rockwell’s managed images are updated to fixed Cisco IOS XE builds. Rockwell has directed managed customers to coordinate for remediation cadence.
• If you are not managed by Rockwell:
• Immediately inventory Stratix and any Rockwell solutions that embed Cisco switching code.
• Apply network‑level access restrictions for SNMP (block from internet, whitelist management hosts).
• Plan and test vendor patches in a staging lab. Prioritize devices that form the OT backbone or connect multiple production zones.

Numbered remediation priorities for the first week

• Identify all devices with SNMP enabled and verify whether they run vulnerable IOS/XE builds.
• Block SNMP at the edge and apply strict ACLs limiting SNMP to trusted management hosts.
• Rotate SNMP credentials and remove unused community strings.
• Schedule vendor patches, test in lab, and roll out to production during controlled maintenance windows.
• Enhance monitoring (SNMP anomaly detection, centralized logging, NDR signatures).

---

Strengths and weaknesses of vendor and agency responses​

Strengths​

• Fast coordination between Cisco, Rockwell, and national CERTs yielded patches, advisories, and KEV classification in short order — a necessary alignment for OT operators.
• Rockwell’s explicit mapping of affected Stratix FRNs and its managed‑service remediation pathway provides clarity for customers that rely on Rockwell to control image versions and rollout.

Weaknesses and friction points​

• Patching network infrastructure inside OT environments is operationally disruptive; some devices require careful compatibility checks and staged validation, which lengthens time‑to‑remediate and increases exposure windows.
• The fix cadence for embedded Stratix IOS builds may lag Cisco’s fixes because Rockwell must integrate, test, and publish corrected FRNs for each product line — an unavoidable but real operational friction.
• Detection gaps: Many OT environments lack mature network detection tuned for protocol abuses such as malformed SNMP traffic, meaning early exploitation may be missed.

---

Strategic implications for OT security programs​

This advisory highlights persistent systemic risks for industrial operators:

• Third‑party software reuse creates supply‑chain concentration risk: a single upstream library or OS component vulnerability can cascade across multiple vendor product lines.
• Asset and configuration management remain the most effective immediate defenses: knowing what runs SNMP, where it is reachable from, and who holds the credentials reduces attack surface dramatically.
• Long term, organizations must invest in OT‑aware vulnerability management, staged testing capabilities, and operational processes that let them apply security updates without endangering safety or production.

Practical investments to consider

• OT asset inventory that ties firmware/IOS builds to hardware serial numbers and maintenance windows.
• Staged testbeds for validating Stratix/IDC firmware updates and rollback procedures.
• Enhanced supplier management clauses that require prompt disclosure and coordinated remediation timelines for embedded third‑party vulnerabilities.

---

Conclusion​

CVE‑2025‑20352 is a reminder that a vulnerability in a widely reused component — in this case, Cisco’s SNMP implementation — can quickly propagate into industrial ecosystems and require both immediate tactical defense and longer‑term strategic changes. Rockwell Automation’s Lifecycle Services with embedded Cisco technology are affected where Cisco IOS XE builds are present; managed customers should coordinate with Rockwell, while unmanaged customers must inventory, restrict SNMP exposure, rotate credentials, and push vendor patches after careful testing. The path forward is the familiar one for reliable OT security: inventory, isolate, patch, and harden — but executed with the urgency and operational care that industrial control systems demand.
If you are responsible for OT assets that include Rockwell Lifecycle Services or Stratix switching, treat this advisory as high priority: confirm which devices in your estate are affected, remove unnecessary SNMP exposure immediately, and schedule validated vendor updates as the primary remediation path. The combination of documented in‑the‑wild exploitation and the potential for root‑level compromise makes rapid, coordinated action the safest route for both operations and security teams.

---

Source: CISA Rockwell Automation Lifecycle Services with Cisco | CISA