Secure Vendor Access: How Singapore Companies Should Control Third-Party Remote Access

The Vendor Access Problem Nobody Talks About

When a breach investigation reveals the entry point, "third-party remote access" appears with uncomfortable frequency. The SolarWinds attack. The Target breach. Countless ransomware incidents across Southeast Asia. In each case, the attacker did not defeat the company's own perimeter — they walked in through a vendor's door that was left open too wide, for too long, with too little oversight.

Singapore businesses — from SMEs using managed IT providers to financial institutions with dozens of software vendors — carry this same risk every day. The threat is not theoretical. MAS TRM Guidelines §13 and ISO 27001 Annex A control A.8.18 both explicitly require organisations to manage privileged access for third parties. Yet in practice, many Singapore companies still grant vendor access in ways that create significant exposure.

This article walks through the most common gaps and the practical controls that close them — without making your vendors' jobs impossible in the process.

Why Third-Party Access Is a High-Risk Attack Surface

Vendors by their nature have legitimate reasons to access your systems: IT support providers need to log in to manage your infrastructure, software vendors need to deploy updates or diagnose issues, audit firms need to pull reports, and cloud providers may have backend access for maintenance purposes. That legitimacy is precisely what makes these accounts attractive to attackers.

The key risks Singapore businesses face

• Overprivileged accounts: Vendors are often granted broad administrative access "to make things easier" — access that persists long after it is needed.
• Shared credentials: Multiple vendor technicians using a single username and password, making it impossible to attribute actions or detect anomalies.
• No session monitoring: Vendor access sessions run unrecorded, with no visibility into what was done or accessed during the session.
• Inactive accounts that persist: Accounts created for a one-time project that are never deprovisioned — sitting dormant, waiting to be exploited.
• No MFA on vendor accounts: Credentials stolen from a vendor's own compromised systems can be used directly against yours.
• Flat network access: Vendors connected to your network via VPN or RDP can often pivot laterally far beyond what they actually need to reach.

The Controls That Actually Work

Effective vendor access management is not a single tool — it is a layered set of processes and technical controls working together. Here is what mature organisations in Singapore implement:

1. Just-In-Time (JIT) Access Provisioning

Instead of granting vendors standing access accounts that exist permanently, JIT provisioning creates access only when it is needed and automatically revokes it when the session ends or the work order closes. This eliminates the "dormant account" risk entirely. When a vendor needs to perform maintenance, they submit a request, access is provisioned for the duration, and it disappears afterwards. No permanent foothold, no persistent attack surface.

2. Privileged Access Management (PAM) Solutions

A PAM platform sits between your vendor and your systems, acting as a gatekeeper. Vendors authenticate to the PAM solution, which then passes them through to target systems using credentials they never actually see. Key capabilities include:

• Credential vaulting — vendors never hold your actual passwords
• Session recording — every keystroke and screen action is logged and replayable
• Session brokering — vendors access systems through the PAM proxy, preventing direct connections
• Approval workflows — sensitive access requires manager sign-off before it is granted

Solutions like CyberArk, BeyondTrust, and Delinea are widely deployed in Singapore's financial and government sectors. For SMEs, lighter-weight alternatives offer many of the same principles at lower cost.

3. Multi-Factor Authentication — Non-Negotiable

Every vendor account that can access your systems must use MFA. If a vendor's own credentials are stolen — whether through phishing, a dark web data breach, or an insider at the vendor — MFA is the control that prevents those credentials from being used against you. This applies to VPN access, RDP, cloud management portals, and any web-based admin interface.

4. Network Segmentation for Vendor Access

Vendors should only be able to reach the specific systems they need to support — nothing else. A network printer vendor has no legitimate reason to access your financial database. Achieve this through dedicated VLANs for vendor traffic, firewall rules that restrict access to specific IP ranges or system segments, and micro-segmentation where your architecture supports it.

If a vendor is compromised, network segmentation limits the blast radius. They can only reach what you have explicitly allowed.

5. Formal Access Review Cycles

All vendor access accounts should be reviewed on a defined schedule — at minimum quarterly, more frequently for privileged accounts. Reviews should confirm that the vendor relationship is still active, the access level remains appropriate, MFA is enabled, and the account has been used recently. Accounts that fail these checks should be suspended or removed immediately.

This is an explicit ISO 27001 A.8.3 requirement and maps to MAS TRM §13 obligations for ongoing vendor oversight.

6. Contractual Security Requirements

Your vendor contracts should include explicit cybersecurity obligations: mandatory MFA on any accounts used to access your systems, incident notification timelines (typically 24–72 hours), requirements to notify you if the vendor suspects their own systems are compromised, and cooperation with your security audits. Without contractual teeth, even good intentions can result in poor practices that you have no standing to enforce.

A Practical Implementation Roadmap for Singapore Businesses

Not every organisation can deploy a full PAM solution overnight. Here is a pragmatic sequence that reduces risk at each stage:

Immediate (Week 1–2)

• Audit all existing vendor accounts — identify every account that was created for third-party access
• Disable any account that has not been used in the past 90 days
• Enforce MFA on all remaining vendor accounts immediately
• Review and restrict VPN split-tunneling so vendor connections cannot reach internal segments unnecessarily

Short-Term (Month 1–3)

• Implement a formal request-and-approval process for new vendor access — no more ad hoc account creation
• Define access expiry dates for all vendor accounts at creation time
• Enable logging on all systems vendors can access — at minimum, capture login events and privileged command execution
• Review vendor contracts and add security requirements to those that lack them

Medium-Term (Quarter 2–3)

• Evaluate and deploy a PAM solution appropriate to your scale and budget
• Implement network segmentation to isolate vendor-accessible systems
• Establish a quarterly vendor access review process with documented sign-offs
• Conduct a vendor risk assessment for your top five to ten third parties

How Infinite Cybersecurity Helps Singapore Businesses

Infinite Cybersecurity provides end-to-end vendor access management reviews and implementation support for Singapore businesses across sectors including financial services, healthcare, government-linked organisations, and technology companies.

Our engagements typically cover a full audit of all existing vendor access accounts and entitlements, gap assessment against MAS TRM §13, ISO 27001 A.8.18, and Singapore's Cyber Trust Mark requirements, design and implementation of JIT provisioning workflows and PAM architecture, network segmentation review to isolate vendor access paths, and access review process design with policy templates and vendor contract clauses.

We are CREST-accredited and hold the Singapore Cyber Trust Mark — the same standard we help our clients achieve. Our consultants have delivered privileged access programmes for some of Singapore's most security-conscious organisations, and we understand what works in practice, not just on paper.

Whether you are responding to a MAS TRM audit finding, preparing for ISO 27001 certification, or simply concerned about vendor access sprawl in your environment, we can help you build the controls that matter.