Vendor Cyber Risk: Is Your Supply Chain Secure?

Your Security Is Only as Strong as Your Weakest Vendor

You can invest heavily in securing your own business — firewalls, MFA, endpoint protection, staff training — and still suffer a devastating breach because one of your vendors was compromised. This is not a theoretical risk. Supply chain attacks are now among the most common and damaging cyber threats facing Australian businesses.

The Australian Signals Directorate (ASD) has repeatedly warned that supply chain compromise is a growing vector for cyber attacks against Australian organisations of all sizes. When a vendor with access to your systems, data or network is breached, the attacker effectively inherits that access.

Why Vendor Breaches Hit SMEs Hardest

Large enterprises have dedicated third-party risk management (TPRM) teams, vendor security assessments and contractual protections. Most SMEs have none of these. Yet SMEs are just as reliant on third-party software, cloud services, IT providers and business partners as their larger counterparts.

Consider the vendors your business likely depends on:

• Cloud platforms: Microsoft 365, Google Workspace, accounting software, CRM systems
• IT service providers: Managed service providers (MSPs), web developers, hosting companies
• Payment processors: EFTPOS providers, online payment gateways
• Professional services: Accountants, lawyers, HR platforms with access to sensitive data
• Suppliers and logistics: Procurement platforms, freight companies, warehouse management systems

Each of these represents a potential entry point for an attacker. If your IT managed service provider is compromised, the attacker may gain administrative access to every one of their clients — including you.

Major Australian Supply Chain Incidents

Australia has seen several high-profile supply chain incidents that underscore the risk:

• MediSecure (2024): The electronic prescriptions provider suffered a ransomware attack that exposed the personal and health data of approximately 12.9 million Australians. Thousands of healthcare providers who relied on MediSecure were affected without being directly attacked.
• HWL Ebsworth (2023): One of Australia’s largest law firms was hit by the ALPHV/BlackCat ransomware group. The breach exposed sensitive data belonging to numerous government agencies and corporations that were clients of the firm.
• Accellion/MOVEit (2023): A vulnerability in a widely used file transfer platform affected multiple Australian organisations, demonstrating how a single software supply chain weakness can cascade across hundreds of organisations globally.

In every case, the organisations that suffered data exposure were not directly attacked. They were compromised through a trusted third party.

Assessing Vendor Security Posture

You do not need an enterprise-grade TPRM program to manage vendor risk effectively. Start with these practical steps:

1. Inventory Your Vendors

Create a simple register of all third parties that have access to your data, systems or network. For each vendor, document:

• What data or systems they can access
• How they connect to your environment (VPN, API, remote desktop, physical access)
• Whether they store your data and where
• The criticality of the service they provide

2. Ask the Right Questions

For your most critical vendors (those with access to sensitive data or core systems), send a security questionnaire. You do not need a 200-question enterprise assessment. A focused set of 15 to 20 questions covering the essentials is far more practical for SMEs:

• Do they enforce multi-factor authentication for all staff and administrative access?
• Do they encrypt data at rest and in transit?
• Do they have a documented incident response plan?
• How quickly will they notify you of a breach affecting your data?
• Do they hold any security certifications (SMB1001, ISO 27001, SOC 2)?
• Do they conduct regular vulnerability assessments or penetration testing?
• What is their patch management process?
• Do they use sub-processors, and if so, how do they assess those sub-processors?

3. Check for Certifications

Vendor certifications are not a guarantee of security, but they demonstrate a baseline commitment. Look for:

• SMB1001 (any tier) — particularly relevant for Australian SME vendors
• ISO 27001 — the international standard for information security management
• SOC 2 Type II — common among SaaS and cloud providers
• Essential Eight alignment — demonstrates adherence to ASD recommended controls

For a detailed comparison of these frameworks, see our framework comparison guide.

4. Continuous Monitoring

Vendor risk is not a one-time assessment. Security postures change, new vulnerabilities are discovered, and vendors undergo their own changes (acquisitions, staff turnover, technology migrations). Review your critical vendors at least annually, and set up alerts for news of breaches affecting your key suppliers.

Contract Requirements: Cyber Clauses That Protect You

Your contracts with vendors should include specific cyber security provisions. These do not need to be complex legal documents — clear, plain-English clauses are effective. Essential contract provisions include:

Breach Notification

Require vendors to notify you of any security incident affecting your data within a defined timeframe — ideally 24 to 48 hours. Without this clause, you may not learn about a breach until weeks or months later, by which time the damage is compounded.

Minimum Security Standards

Specify the minimum security controls you expect: MFA, encryption, patching cadence, access controls and backup practices. This sets a baseline and gives you grounds to act if the vendor falls short.

Right to Audit

Include the right to request evidence of security practices — either through self-attestation, certification or independent audit. You may never exercise this right, but having it in the contract is powerful leverage.

Data Handling and Deletion

Specify how the vendor must handle your data, where it can be stored (Australian data sovereignty is a consideration), and what happens when the contract ends. Require confirmation of data deletion upon termination.

Liability and Indemnity

Ensure the contract addresses liability in the event of a vendor-caused breach. This is an area where legal advice specific to your situation is worthwhile.

Building a Vendor Risk Management Program for SMEs

A practical TPRM program for an SME does not need to be bureaucratic. Here is a lean approach:

1. Categorise vendors by risk: High (access to sensitive data or critical systems), Medium (limited data access), Low (no data access). Focus your effort on high-risk vendors.
2. Standardise your questionnaire: Create a single, reusable vendor security questionnaire. Send it to all new high-risk vendors and to existing ones annually.
3. Use a simple register: A spreadsheet with vendor name, risk category, last assessment date, key findings and next review date is sufficient for most SMEs.
4. Include in onboarding: Make vendor security assessment part of your procurement process. Do not sign contracts with high-risk vendors without completing an assessment.
5. Plan for incidents: Your incident response plan should include scenarios involving vendor breaches. Know who to contact at each critical vendor and what your communication plan is if their breach affects your customers.

Third-party risk management is fundamentally a governance discipline. In the IDIA framework, it sits within the Assurance pillar — alongside compliance, risk management and continuous improvement. This means vendor assessments, contract reviews and ongoing monitoring should be treated as core governance controls, not ad hoc activities triggered only when something goes wrong. Structuring vendor risk under Assurance ensures it receives the same rigour and regular review cadence as your internal security controls.

“You cannot outsource accountability. When a vendor breach exposes your customers’ data, your customers do not blame the vendor — they blame you.”

Understand Your Exposure

Managing vendor risk starts with understanding your own security posture. Platforms like How’s My Cyber use the IDIA framework (Identity, Data, Infrastructure, Assurance) to organise every control — including third-party risk management — into a clear operating model that works alongside any standard. Start with the free CYBER9 assessment to benchmark your business across nine critical domains in under 10 minutes. You will receive a clear maturity score and actionable recommendations, including guidance on how to assess and manage the cyber risk introduced by your vendors and supply chain partners.