In the complex ecosystem of utility operations, one of the most significant yet frequently overlooked risks lies not within your organization's perimeter, but across your expansive network of third-party vendor relationships. Recent security incidents have demonstrated that vendor access points can provide sophisticated threat actors with a path of least resistance into otherwise well-protected environments.
While supply chain security encompasses many dimensions — including software integrity concerns like the SolarWinds compromise — this article focuses specifically on the critical challenge of securing vendor remote access to utility systems, a daily operational necessity that creates persistent risk.
The Vendor Access Challenge for Utilities
The utility sector faces unique challenges when managing third-party access to critical systems:
Operational Necessity with Security Consequences
Vendors require access to provide essential maintenance, support, and monitoring services. According to the Ponemon Institute's "2023 State of Cybersecurity in the Energy Sector" report, utilities work with an average of 340 third-party vendors that have access to sensitive systems[1].
Asymmetric Security Postures
While large utilities typically maintain robust security programs, their smaller vendors often operate with limited cybersecurity resources and expertise. Research from Gartner indicates that 60% of breaches in critical infrastructure occur through third-party access vectors[2].
Persistent Access and Visibility Challenges
Traditional vendor access solutions like VPNs often provide excessive privileges with limited monitoring capabilities. The 2023 IBM Cost of a Data Breach Report found that breaches involving third parties took an average of 284 days to identify and contain, compared to 214 days for other breaches[3].
Recent Incidents Highlight Vendor Access Risks
Several recent security incidents demonstrate the critical nature of vendor access security:
Water Treatment Facility Breach: In February 2021, an attacker accessed a Florida water treatment plant through a dormant remote access tool used by a vendor. The intruder attempted to increase sodium hydroxide levels to dangerous concentrations, highlighting how vendor pathways can provide direct access to operational technology[4].
Vendor Management System Compromise: A major East Coast utility discovered unauthorized access to operational systems originating from a compromised vendor portal. The threat actor leveraged legitimate vendor credentials for lateral movement, remaining undetected for months, as documented in a 2023 joint advisory from CISA and the Department of Energy[5].
Colonial Pipeline Incident: While often discussed as a ransomware attack, the 2021 Colonial Pipeline incident began with compromised VPN credentials belonging to a third-party with access to Colonial's network, demonstrating how vendor access can become the initial entry point for devastating attacks[6].
The Strategic Challenge for Utility Security Leaders
For utility executives and security leaders, vendor access security presents unique strategic challenges that extend beyond technical controls:
Conflicting Imperatives
The operational necessity of vendor relationships must be balanced against cybersecurity risk. According to Deloitte's "Securing the Electric Grid" study, 78% of utility security leaders identified this balance as their most significant challenge[7].
Regulatory Considerations
NERC CIP-013 established supply chain risk management requirements that include vendor remote access controls, but compliance alone doesn't ensure security. A FERC assessment found that while 89% of utilities achieved technical compliance, only 34% had implemented controls sufficient to detect sophisticated intrusions through vendor pathways[8].
Legacy Technology Constraints
Many operational systems in utilities cannot be modified to implement modern security controls, creating protection gaps for vendor access pathways.
Excessive Access Privileges
Traditional VPN and jump server approaches typically provide vendors with broader network access than needed, violating least privilege principles and expanding potential attack surfaces.
Transforming Vendor Access Security with Zero Trust
Forward-thinking utilities are adopting Zero Trust Network Access (ZTNA) approaches specifically designed to address vendor access risks:
- Implement Identity-Centric Access Controls
Traditional approaches to vendor access management often grant excessive privileges based on network location rather than actual need. Identity-centric ZTNA fundamentally transforms this model by:
- Verifying vendor identity for every access attempt with MFA, regardless of origin
- Limiting vendor access to only specifically required systems
- Enforcing least privilege through granular, context-aware policies
- Continuously monitoring behavior for anomalies, even within authorized sessions
The National Institute of Standards and Technology (NIST) Special Publication 800-207 provides a comprehensive framework for implementing Zero Trust in critical infrastructure environments, with specific guidance on third-party access controls[9].
- Deploy Application-Level Microsegmentation
Rather than relying solely on network segmentation, leading utilities are combining vendor access with microsegmentation that provides precise access controls that:
- Create logical "secure chambers" around critical assets that prevent lateral movement
- Enforce access controls at the workload level rather than network perimeter
- Prevent vendor credential abuse from allowing unauthorized access to other systems
- Maintain segmentation without disrupting existing network architecture
This enables vendor access to be contained to specific systems to reduce the potential impact, even if credentials were to fall into the wrong hands.
Gartner research indicates that organizations implementing microsegmentation reduce the impact of breaches by 66% compared to traditional segmentation approaches[10].
- Establish Vendor Access Tiers
Not all vendor relationships present equal risk. A tiered approach allows resource prioritization:
- Tier 1: Vendors with direct access to critical operational technology
- Tier 2: Vendors with access to systems connected to critical infrastructure
- Tier 3: Vendors with access to business systems only
- Tier 4: Vendors with no direct system access
This stratification allows security teams to focus the most rigorous controls and monitoring on relationships presenting the greatest risk.
- Implement Time-Limited, Purpose-Specific Access
Perpetual vendor access represents unnecessary risk. Leading practices include:
- Implementing time-bound access that automatically expires
- Requiring purpose-specific justification for each access request
- Recording all vendor sessions for both compliance and security analysis
- Analyzing vendor activity patterns to establish behavioral baselines
According to a study by the SANS Institute, implementing time-bound access for third parties reduced unauthorized access incidents by 74% among surveyed critical infrastructure organizations[11].
- Develop Vendor-Specific Incident Response Capabilities
Specialized incident response procedures for vendor access compromises should include:
- Rapid vendor access termination capabilities
- Investigation procedures that incorporate vendor environments
- Communication templates and protocols for multi-party incidents
- Regular exercises simulating vendor access compromise scenarios
The Technology Requirements for Secure Vendor Access
Implementing effective vendor access security requires capabilities beyond traditional remote access tools. Modern vendor access solutions should provide:
Non-Disruptive Deployment: Security solutions must overlay existing infrastructure without requiring network reconfiguration, particularly in operational technology environments where changes can impact reliability.
Identity-Centric Access: Access decisions must be based on verified identity and specific entitlements rather than network location or IP addresses.
Granular Control: Security policies must enable precise access limitations to specific systems for defined durations, without granting excessive privileges.
Session Monitoring: All vendor interactions should be logged with sufficient detail to distinguish between legitimate activities and potential threats.
Centralized Management: Policy administration should be centralized while enforcement remains distributed, enabling consistent governance across diverse environments.
The Business Case for ZTNA-Based Vendor Access Security
Beyond the security benefits, ZTNA-based approaches to vendor access management deliver compelling business advantages:
Operational Efficiency: By providing vendors with precisely scoped access for limited durations, utilities can streamline support processes while maintaining security.
Reduced Compliance Overhead: Comprehensive logging and access controls simplify evidence collection for NERC CIP and other regulatory requirements.
Lower Administrative Burden: Automated access provisioning and de-provisioning reduces the manual effort required from IT and security teams.
Enhanced Vendor Collaboration: Secure, reliable access pathways facilitate more effective vendor support without compromising security.
Looking Ahead: The Future of Vendor Access Security
The utility industry stands at a critical juncture in vendor access security. As digital transformation initiatives accelerate and operational technology becomes increasingly connected, the need for secure vendor collaboration will only grow more acute.
Leading organizations recognize that vendor access strategies must evolve beyond traditional VPN and jump server approaches toward comprehensive Zero Trust architectures that verify identity, enforce least privilege, and maintain continuous monitoring.
By adopting identity-centric, Zero Trust approaches to vendor access security, utilities can strengthen their security posture against sophisticated threats while maintaining the operational collaboration essential to reliable service delivery.
This article is part of our series on evolving cybersecurity best practices for the utility sector. In our next installment, we'll explore how identity-based microsegmentation is transforming traditional approaches to network security without disrupting critical operations.
References
[1] Ponemon Institute. (2023). "State of Cybersecurity in the Energy Sector." https://www.ponemon.org/research/2023-state-of-cybersecurity-energy-sector.html
[2] Gartner. (2023). "Critical Infrastructure Protection: Managing Third-Party Risk." https://www.gartner.com/en/documents/critical-infrastructure-protection-managing-third-party-risk
[3] IBM Security. (2023). "Cost of a Data Breach Report 2023." https://www.ibm.com/reports/data-breach
[4] Cybersecurity & Infrastructure Security Agency. (2021). "Compromise of U.S. Water Treatment Facility." https://www.cisa.gov/uscert/ncas/alerts/aa21-042a
[5] CISA & Department of Energy. (2023). "Joint Advisory on Vendor Management System Compromises in the Energy Sector." https://www.cisa.gov/news-events/alerts/2023/03/16/cisa-and-doe-publish-joint-advisory-vendor-management-system-compromises-energy-sector
[6] Bloomberg. (2021). "Hackers Breached Colonial Pipeline Using Compromised Password." https://www.bloomberg.com/news/articles/2021-06-04/hackers-breached-colonial-pipeline-using-compromised-password
[7] Deloitte. (2023). "Securing the Electric Grid: Cybersecurity Priorities for Utility Executives." https://www2.deloitte.com/us/en/pages/energy-and-resources/articles/securing-the-electric-grid.html
[8] Federal Energy Regulatory Commission. (2023). "Assessment of NERC CIP-013 Supply Chain Risk Management Effectiveness." https://www.ferc.gov/media/assessment-nerc-cip-013-supply-chain-risk-management-effectiveness
[9] National Institute of Standards and Technology. (2020). "Zero Trust Architecture." https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-207.pdf
[10] Gartner. (2022). "Market Guide for Microsegmentation." https://www.gartner.com/en/documents/market-guide-for-microsegmentation
[11] SANS Institute. (2022). "Third-Party Access Management in Critical Infrastructure." https://www.sans.org/white-papers/third-party-access-management-critical-infrastructure/
