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Spotlight
PAGE: https://alison.com/course/computer-networking-local-area-networks-and-the-osi-model-revised
PROMISE: Map network logic to see how local exploits bypass standard security boundaries.
WHO: Security professionals or advanced beginners who need to connect theoretical network models to real-world local exploit scenarios.
WHYNOW: The course is freely accessible and provides the foundational logic required to interpret current local network threats without paid certification.
DESC: Browse now online local area networks OSI model training course that includes LAN networking key features, ethernet functions and seven layers of the OSI Model.
BEFORE: The reader watches a local exploit occur but cannot name the responsible hardware.
BEFORE: The reader sees network frames but does not understand the structural rules of Ethernet.
BEFORE: The reader lacks a mental model for where in the stack security boundaries exist.
AFTER: The reader can point to the specific router or switch that failed to isolate the traffic.
AFTER: The reader can parse frame structures to spot malformed or malicious data patterns.
AFTER: The reader maps the exploit to a specific OSI layer function to understand the breach.
GAIN: Ability to explain how Hubs, Switches and Routers function to isolate local exploits.
GAIN: Skill to describe how Ethernet functions to verify frame integrity during an attack.
GAIN: Knowledge to list the seven layers of the OSI Model for precise incident mapping.
STEP: You cannot trace which device allowed the malicious server to reach local data. || Explain how Hubs, Switches and Routers function || Identify the specific forwarding or filtering point where the unauthorized traffic entered the local segment.
STEP: The malicious request looks like normal traffic but carries hidden instructions. || Describe how Ethernet functions || Distinguish between valid frame headers and anomalous payloads that trigger local system vulnerabilities.
STEP: You need to know where in the stack the data was intercepted. || Describe the functions of each layer of the OSI Model || Locate the exact layer where the exploit interacted with the local network interface.
NOTFOR: Professionals who already have deep hands-on experience with packet capture and network forensics.
NOTFOR: Users looking for immediate software patching instructions rather than theoretical network architecture.
FACT: Average duration: 1.5-3 Hours (Contains Video)
FACT: CPD-accredited certificate available
FACT: Beginner level
COVERS: Having completed this course you will be able to:
COVERS: Define what Local Area Network (LAN) means
COVERS: Describe the key devices found on a LAN
COVERS: Explain how Hubs, Switches and Routers function
COVERS: Describe how Ethernet functions
COVERS: Describe the structure and function of IP Addresses
COVERS: List the seven layers of the OSI Model
COVERS: Describe the functions of each layer of the OSI Model
COVERS: List the four layers of the TCP Model
COVERS: Describe the functions of each layer of the TCP Model
COVERS: Explain the differences between the OSI Model and the TCP Model
COVERS: Computer Networking
MODULE: Introduction to Local Area Networks || Introduction to Local Area Networks | Network Terminology | Serial Data Transfer and IP Addresses | Types of Networks | Types of Computing
MODULE: Defining Networks with Osi Model || Introduction to OSI Model | OSI Layer 1 and Layer 2 | OSI Layer 3 and Layer 4 | OSI Layer 5, Layer 6 and Layer 7
What you are probably seeing
You notice unexplained traffic spikes on your local machine that do not match your expected test workload.
Your monitoring tools flag data writes and reads from unfamiliar source addresses that are not your internal users.
Why it happens
The application’s client software exposes its API on a public network port without requiring authentication.
Browsers often relax security restrictions for localhost, allowing a remote attacker to use your browser as a proxy to reach that open local port.
What changed recently
2026-10-07 · 306
CISA alerts warn that server interfaces lack isolation:
• CWE-306 shows missing auth for heavy tasks.
• Secondary ports often skip user checks.
• Client checks must duplicate on the server.
Source: ticket:www.cisa.gov
2026-10-07 · CVE-2026-105851: CVE-2026-105851: Privilege Escalation via Field Access Control Bypass in Payload CMS Duplication Mechanism
Payload CMS 3.90.0 closes the privilege gap:
• Standard users can duplicate admin profiles
• Set disableDuplicate: true in configs
• Duplicate requests return 400 or 404
Source: how_devto_security
2026-10-06 · ClickFix Attacks Evolve to Better Hide Malicious Payloads
Threat actors now hide payloads in browser cache for that gap:
• PowerShell queries DNS TXT records to hide next steps
• Payloads are pre-cached as disguised PNG images
• Microsoft Defender protects elements across the attack chain
Source: darkreading
2026-10-06 · MCP Python SDK OAuth Flaw Lets Malicious Servers Hijack AI Agent Accounts
MCP Python SDK flaw now threatens AI agent accounts:
• Versions 1.9.1 to 1.29.1 are affected.
• Upgrade to 1.30.0 or 2.2.0 to patch.
• Rotate exposed client secrets after patching.
Source: CyberSecurityNews
2026-10-06 · Researcher Discloses Same MCP Flaw at Google, JPMorgan, Two Governments
Google patched the gap in its MCP tooling:
• mcp-toolbox v1.5.0 adds an SSRFGuard.
• The fix re-checks every redirect hop.
• CVSS 8.0 rates the flaw High severity.
• Five federal servers remain in triage.
Source: unite.ai
2026-10-06 · Which host is https://trusted@evil.com? Our approval screen and our provisioner disagreed
A new guide exposes how URL parsing flaws confuse host checks:
• URLs with userinfo now rejected
• Approval and provisioning screens aligned
• Nine regression tests added for host mismatch
Source: how_devto_security
2026-10-06 · CVE-2026-94293: AAS Edge Client — CVSS 9.8 IIoT Data Tampering, No Patch, Decommission Now
Researchers exposed the gap with a high-risk CVE:
• AAS Edge Client runs an unauthenticated API on port 18000.
• Any attacker can read and overwrite submodel data.
• Vendor recommends decommissioning due to a 9.8 CVSS score.
Source: how_devto_security
Step by step
1. Audit your running services to identify any local ports that accept unauthenticated requests.
2. Bind those local services strictly to the loopback address rather than the host’s primary IP.
3. Add a firewall rule to block external traffic to the identified local management ports.
4. Disable or upgrade any legacy software that exposes internal data interfaces without verification.
5. Review browser extension permissions to ensure they do not bypass network isolation settings.
Ways to go further
Start here: Computer Networking – Local Area Networks and the OSI Model For when you need to map the underlying network logic behind the local exploit. Open the free course on Alison ↗
Better fit: Creating a Local SQLite Database with Node.js For when you are building a local tool that interacts with the system. Open the free course on Alison ↗
Affiliate links: CHEAPUNO may earn a commission if you buy through them, at no extra cost to you.
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