Researchers preparing a Black Hat Europe briefing recently walked through a scenario that should bother anyone who treats cloud-managed firewalls and routers as a “safe middle” between the Internet and their IoT fleet. Instead of attacking devices directly, they showed how an adversary can hijack cloud management channels, impersonate firewalled equipment and push administrative commands to routers, cameras and other IoT nodes without t ouching a single software vulnerability on the devices themselves.
In this model, the firewall stops looking like a hard perimeter and starts looking like a remote-control relay. The “Cloud Break” idea turns the trusted relationship between IoT devices and vendor cloud platforms into an attack surface. For security teams that rely heavily on cloud-managed firewalls and routers, this shifts the problem from “harden the device” to “treat the management plane as a high-value target.”
Because this technique does not rely on exposed IP addresses, open ports or unpatched firmware, it bypasses many assumptions that underpin traditional IoT hardening guidance. That makes it worth unpacking in detail.
𝗙𝗿𝗼𝗺 𝗳𝗶𝗿𝗺𝘄𝗮𝗿𝗲 𝗯𝘂𝗴𝘀 𝘁𝗼 𝗰𝗹𝗼𝘂𝗱 𝗶𝗱𝗲𝗻𝘁𝗶𝘁𝘆: 𝘄𝗵𝘆 𝘁𝗵𝗲 𝗺𝗼𝗱𝗲𝗹 𝗶𝘀 𝗱𝗶𝗳𝗳𝗲𝗿𝗲𝗻𝘁
Most IoT compromise still follows a familiar pattern: scan for exposed IP addresses, fingerprint devices, then exploit firmware issues or weak credentials. Organisations that patch diligently, hide management interfaces and segment their networks often assume they sit outside the highest-risk cohort.
The Cloud Break model moves the threat upstream. Instead of talking to the device over the open Internet, the attacker talks to the vendor’s cloud management service and pretends to be the device. Once that impersonation succeeds, the cloud service itself relays commands into the internal network.
That shift matters because:
• the attacker never needs direct IP-level access to the IoT device,
• the device can sit behind a firewall or even on an intranet segment with no raw Internet connectivity, and
• the exploit chain targets identity and protocol logic in the cloud instead of software bugs on the device.
In other words, the attacker borrows the vendor’s control plane instead of fighting through your perimeter.
𝗛𝗼𝘄 𝗰𝗹𝗼𝘂𝗱-𝗺𝗮𝗻𝗮𝗴𝗲𝗱 𝗳𝗶𝗿𝗲𝘄𝗮𝗹𝗹𝘀 “𝗸𝗻𝗼𝘄” 𝘁𝗵𝗲𝗶𝗿 𝗱𝗲𝘃𝗶𝗰𝗲𝘀
Cloud management platforms need a way to recognise each appliance they control. For many IoT-focused firewalls, routers and gateways, that identity check relies on simple, static attributes such as a serial number or MAC address.
A typical flow looks like this:
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The device boots and contacts a vendor cloud endpoint.
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It presents its serial number or MAC address and runs a basic credential derivation routine baked into firmware.
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The cloud checks the values, maps the connection to a tenant account and opens a management channel.
This design appeals to hardware vendors because it keeps manufacturing, logistics and cloud onboarding straightforward. However, it also assumes that:
• serial numbers and MAC addresses remain obscure, and
• the derivation logic for credentials stays out of reach of attackers.
Both assumptions already look weak. Research teams have shown that manufacturers frequently expose device identifiers through local network interfaces, mobile pairing flows or cloud registration endpoints. Serial numbers often follow predictable patterns, and MAC address prefixes reveal the vendor, leaving only a small space for brute-force guessing.
Once an adversary can harvest or guess identifiers at scale, the identity layer of the “secure” cloud channel no longer looks particularly secure.
𝗙𝗿𝗼𝗺 𝘀𝗲𝗿𝗶𝗮𝗹 𝗻𝘂𝗺𝗯𝗲𝗿 𝘁𝗼 𝗰𝗵𝗮𝗻𝗻𝗲𝗹 𝗵𝗶𝗷𝗮𝗰𝗸: 𝘁𝗵𝗲 𝗫𝗲/𝗪𝗮𝗻𝗴 𝗮𝘁𝘁𝗮𝗰𝗸 𝗳𝗹𝗼𝘄
The Black Hat Europe proof-of-concept focuses on two ingredients: a device’s unique identifier and the transformation the vendor uses to derive its cloud credential.
A streamlined attacker workflow looks like this:
First, collect identifiers. The adversary queries exposed interfaces, abuses mobile onboarding APIs or brute-forces predictable serial ranges to compile a list of target device IDs. In some ecosystems, a single misdesigned “claiming” or registration endpoint already reveals which serials exist.
Second, reverse engineer the cloud protocol. By extracting and analysing firmware images for a given firewall or router model, the attacker can reconstruct how the device derives credentials from its serial or MAC, and how it establishes a management channel to the vendor’s cloud.
Third, impersonate the device. Armed with the identifier and the credential algorithm, the attacker connects to the cloud as if they were the device. At that moment, the cloud management service no longer talks to a box sitting in your rack; it talks to the attacker’s emulator.
Fourth, race the legitimate device. Because the real device still maintains its own cloud session, the attacker competes with that channel. By actively disrupting or “disconnecting” the victim’s link at just the right time, the attacker nudges the platform into accepting their connection as the authoritative one.
When that race ends in the attacker’s favour, the cloud portal treats their session as the real device. Any administrative command they send flows through the vendor’s infrastructure and lands on the actual firewall or router sitting deep inside your network.
The key point: the perimeter never breaks in the classic sense. The firewall still drops unsolicited inbound traffic. It simply obeys the “legitimate” instructions coming from its trusted cloud controller because the attacker now wears the device’s identity.
𝗪𝗵𝘆 𝗶𝘁 𝗵𝗶𝘁𝘀 𝗱𝗲𝗽𝗹𝗼𝘆𝗺𝗲𝗻𝘁𝘀 𝘁𝗵𝗮𝘁 “𝗱𝗼 𝗲𝘃𝗲𝗿𝘆𝘁𝗵𝗶𝗻𝗴 𝗿𝗶𝗴𝗵𝘁”
This Cloud Break-style attack worries practitioners because it undermines common risk assumptions. In many environments, teams accept that cheap cameras or sensors on the open Internet will always look risky; they invest heavily in segments and cloud-managed perimeter gear to shield the more important devices.
Here, the attacker aims directly at that protective layer. Even if you:
• keep IoT devices off the public Internet,
• patch firmware promptly, and
• enforce strong local authentication,
the cloud management channel still lets a remote party push configuration changes, update rulesets or pivot traffic.
Once the adversary controls that plane, they can alter NAT rules, open unexpected tunnels, redirect telemetry or quietly downgrade protections for specific devices. In OT-heavy networks, the ability to push configuration to remote routers and industrial gateways from the cloud can translate into real-world impact.
𝗗𝗲𝘁𝗲𝗰𝘁𝗶𝗼𝗻 𝗶𝘀 𝗵𝗮𝗿𝗱 𝗯𝗲𝗰𝗮𝘂𝘀𝗲 𝘁𝗿𝗮𝗳𝗳𝗶𝗰 𝗹𝗼𝗼𝗸𝘀 “𝗻𝗼𝗿𝗺𝗮𝗹”
The researchers emphasise how little this technique stands out at the packet level. Commands ride over the same cloud channels that operations teams already use to manage devices. From the firewall’s perspective, nothing unusual happens: it receives valid instructions from a trusted controller, over an expected connection, wrapped in the vendor’s own protocol.
That makes generic anomaly detection tricky. Simple allow/deny lists and volumetric thresholds rarely catch an attacker who issues a handful of targeted configuration changes.
Detection, therefore, shifts toward:
• monitoring for unusual cloud login sources and device associations,
• alerting on unexpected IP or tenant changes for enrolled devices, and
• correlating management actions with operator activity (for example, “who actually clicked ‘apply’?”).
Vendors that own the cloud platforms sit in the best position to add those checks, yet many ecosystems still rely on static identifiers and opaque backend logic.
𝗠𝗶𝘁𝗶𝗴𝗮𝘁𝗶𝗼𝗻: 𝗯𝗲𝘆𝗼𝗻𝗱 𝗽𝗮𝘁𝗰𝗵𝗲𝘀 𝗼𝗻 𝘁𝗵𝗲 𝗱𝗲𝘃𝗶𝗰𝗲
The core lesson from Cloud Break is simple: IoT authentication to cloud management services needs to evolve beyond serials and MAC addresses. The researchers suggest several directions that fit well with broader best practice from cloud and IoT security communities.
First, strengthen device identity. Instead of deriving credentials directly from serial numbers, vendors should bind devices to random, high-entropy identifiers or per-device keys generated during manufacturing or secure onboarding. Those secrets should never appear in local discovery APIs or simple QR codes.
Second, harden management flows around IP and context changes. When a device suddenly appears with a different source IP range, geography or cloud tenant, the platform should treat that as a high-risk event and require additional verification—either from the operator or from cryptographic proof-of-possession on the device side.
Third, expose better telemetry to customers. Enterprises should see which IPs, accounts and automation systems interact with each cloud-managed device. With that visibility, they can baseline normal behaviour and detect suspicious patterns, instead of relying entirely on vendor assurances.
Fourth, keep traditional network hygiene in place. Cloud Break does not eliminate the value of segmentation, zero trust or device discovery; it simply adds another control point to protect. Segment IoT networks from critical assets, avoid blind trust in management networks and enforce granular policy around what a firewall or router can change programmatically.
𝗣𝗿𝗮𝗰𝘁𝗶𝗰𝗮𝗹 𝗺𝗼𝘃𝗲𝘀 𝗳𝗼𝗿 𝘀𝗲𝗰𝘂𝗿𝗶𝘁𝘆 𝘁𝗲𝗮𝗺𝘀 𝗿𝗶𝗴𝗵𝘁 𝗻𝗼𝘄
Security leaders do not need to wait for vendors to redesign their entire cloud stack before they act. In the short term, you can:
• inventory every firewall, router and IoT gateway that relies on a cloud management portal;
• review which teams and identities hold access to those portals and harden authentication (MFA, phishing-resistant methods where possible);
• ask vendors direct questions about how they derive device credentials and how they protect serial/MAC-based identity schemes;
• build detection around unusual cloud management events especially device re-binding, ownership transfers and IP jumps; and
• treat cloud management paths as part of your critical attack surface in purple-team and red-team exercises.
Viewed that way, Cloud Break becomes less of a niche IoT stunt and more of a warning shot about where perimeter thinking still hides in “modern” architectures.
𝗰𝗹𝗼𝘂𝗱 𝗰𝗼𝗻𝘁𝗿𝗼𝗹 𝗽𝗹𝗮𝗻𝗲𝘀 𝗮𝗿𝗲 𝗻𝗼𝘄 𝗽𝗿𝗶𝗺𝗮𝗿𝘆 𝘁𝗮𝗿𝗴𝗲𝘁𝘀
The Cloud Break research underlines a broader shift: as organisations push more control into vendor-operated clouds, attackers follow. A cloud-managed firewall no longer acts only as a shield; it also acts as an actuator that can rewire your network when someone steals its identity.
Security teams that focus exclusively on device vulnerabilities risk missing this layer entirely. Teams that treat IoT cloud management as part of their core threat surface complete with strong identity, logging, monitoring and vendor pressure move closer to a realistic defence posture for 2025 and beyond.
𝗙𝗔𝗤𝗦
𝗪𝗵𝗮𝘁 𝗶𝘀 𝘁𝗵𝗲 “𝗖𝗹𝗼𝘂𝗱 𝗕𝗿𝗲𝗮𝗸” 𝗶𝗱𝗲𝗮?
Cloud Break refers to an attack model where adversaries impersonate IoT devices to their vendor’s cloud management platform instead of attacking the devices directly. By abusing weak identity schemes based on serial numbers or MAC addresses, attackers can hijack the cloud control channel and push commands to firewalled devices inside private networks.
𝗪𝗵𝘆 𝗮𝗿𝗲 𝗰𝗹𝗼𝘂𝗱-𝗺𝗮𝗻𝗮𝗴𝗲𝗱 𝗳𝗶𝗿𝗲𝘄𝗮𝗹𝗹𝘀 𝗲𝘀𝗽𝗲𝗰𝗶𝗮𝗹𝗹𝘆 𝗲𝘅𝗽𝗼𝘀𝗲𝗱?
Cloud-managed firewalls and routers act as both perimeter devices and remote-controlled endpoints. If an attacker compromises the identity or management channel, they gain the ability to alter rules, routes and policies from outside the network, even when the underlying devices remain fully patched and hidden behind NAT.
𝗗𝗼𝗲𝘀 𝘁𝗵𝗶𝘀 𝗮𝘁𝘁𝗮𝗰𝗸 𝗿𝗲𝗾𝘂𝗶𝗿𝗲 𝗮 𝗻𝗲𝘄 𝗼𝗻-𝗱𝗲𝘃𝗶𝗰𝗲 𝘃𝘂𝗹𝗻𝗲𝗿𝗮𝗯𝗶𝗹𝗶𝘁𝘆?
No. The model targets how cloud platforms authenticate and manage devices rather than bugs in the device firmware. The PoC chain uses public identifiers, predictable serial patterns and reverse-engineered credential logic to impersonate devices at scale.
𝗛𝗼𝘄 𝗰𝗮𝗻 𝗺𝘆 𝘁𝗲𝗮𝗺 𝗱𝗲𝘁𝗲𝗰𝘁 𝗰𝗹𝗼𝘂𝗱 𝗰𝗵𝗮𝗻𝗻𝗲𝗹 𝗵𝗶𝗷𝗮𝗰𝗸𝘀?
You need visibility into the cloud side of the relationship: which IPs log into management portals, which tenants own which devices, when bindings change and how often devices switch source networks. Alerts around unusual re-binding events, unexpected geolocation changes and management actions with no corresponding operator activity help surface this class of attack.
𝗪𝗵𝗮𝘁 𝘀𝗵𝗼𝘂𝗹𝗱 𝘄𝗲 𝗱𝗲𝗺𝗮𝗻𝗱 𝗳𝗿𝗼𝗺 𝘃𝗲𝗻𝗱𝗼𝗿𝘀 𝗮𝗳𝘁𝗲𝗿 𝗖𝗹𝗼𝘂𝗱 𝗕𝗿𝗲𝗮𝗸?
Ask vendors to move away from static identifiers as credentials, to adopt per-device secrets or certificates, to log and expose rich management telemetry, and to implement stronger checks around device IP or tenant changes. Vendors should also publish clear guidance on hardening cloud management access and on how they monitor for device impersonation attempts.
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