Technical debt in Active Directory: A CISO's guide to mitigating board-driven security risks

Active Directory technical debt: A board-facing security challenge

CISOs are under growing pressure not just to secure systems but to navigate the fallout of years of business-first decisions that have quietly stacked up technical debt. In 2025, the pace of mergers, acquisitions, and cost-cutting has left many organizations with sprawling, brittle infrastructures built on outdated protocols and neglected assets. What started as tactical choices in the boardroom—quick wins, deferred upgrades, and rushed integrations—now pose serious risks to resilience, compliance, and innovation.

The result? Hidden vulnerabilities, aging service accounts, legacy authentication methods, and privileged access pathways that no one’s watching. These aren’t just IT problems; they’re enterprise-wide liabilities that invite cyberthreats, regulatory fines, and operational breakdowns.

In this landscape, the CISO’s role is evolving. It’s no longer just about technical oversight—it’s about shaping strategy, influencing board decisions, and building security architectures that can stand up to both scrutiny and scale. This article explores how technical debt often begins with business mandates, how legacy systems quietly erode security posture, and what CISOs can do to take back control. We’ll walk through real-world examples and offer practical steps to reduce risk, drive innovation, and stay aligned with business priorities.

Understanding technical debt in cybersecurity

Technical debt in cybersecurity comprises the backlog of security risks and vulnerabilities resulting from rushed implementations, deferred maintenance, or suboptimal IT decisions. Like financial debt, these risks accrue "interest," making systems increasingly fragile, expensive to maintain, and vulnerable over time. Notably, unresolved technical debt exposes organizations to higher chances of cyberattacks, regulatory penalties, operational disruption, and reputational damage. McKinsey’s research highlights that companies typically spend between 20% and 40% of their IT budgets dealing with technical debt, and nearly 30% of CIOs say over 20% of their new product budgets get diverted to resolving tech debt issues.

Business decisions driving technical debt

Some business situations naturally lead to more technical debt and CISOs need to plan for that.

Organizations often accumulate security debt not through negligence but as a byproduct of strategic decisions, rapid growth, or resource constraints. Below are six recurring scenarios that contribute to fragmented, high-risk IT landscapes:

Mergers and acquisitions

During mergers and acquisitions (M&A) and related activity, CISOs inherit a patchwork of incompatible systems, undocumented data flows, and legacy software. The integration process is rarely immediate. In the interim, security teams must maintain parallel infrastructures, such as dual email platforms, identity providers, or enterprise resource planning systems, which increases complexity and introduces temporary vulnerabilities. These transitional environments often lack unified visibility, consistent patching, and centralized access controls, creating fertile ground for exploitation.

Rapid growth and innovation culture

In fast-scaling organizations, speed often trumps security. Development teams, under pressure to deliver features quickly, may hard-code credentials, bypass secure coding practices, or rely on unvetted open-source libraries. While these shortcuts enable innovation, they also introduce latent vulnerabilities that compound over time, especially when security reviews are deferred or deprioritized.

Shadow IT and decentralized procurement

Departments eager to solve business problems may independently adopt cloud applications or SaaS tools without IT oversight. These shadow IT deployments operate outside the CISO’s visibility, often lacking proper authentication, encryption, or compliance controls. The result is a proliferation of unmanaged endpoints and data silos that weaken the organization’s overall security posture.

Legacy systems and deferred maintenance

Budget constraints or operational inertia can lead to prolonged reliance on outdated systems that no longer receive vendor support or security updates. These legacy environments often lack modern controls, such as MFA, EDR, or network segmentation, making them attractive targets for attackers. Deferred maintenance also limits an organization’s ability to respond to emerging threats or regulatory changes.

Board-mandated budget cuts

When boards push for cost reductions, cybersecurity often takes the first hit. Critical upgrades get postponed, vulnerability fixes pile up, and teams shrink, leaving gaps that attackers are quick to exploit. The damage isn’t always obvious in quarterly metrics, but it shows up fast when incidents strike. What looks like savings on paper can quietly erode resilience.

Feature overload on fragile foundations

In fast-moving, product-led organizations, new features often outpace the stability of the underlying architecture. Teams keep building on top of brittle, poorly documented codebases, adding complexity and risk. Without time for refactoring or threat modeling, these systems become harder to secure, harder to maintain, and nearly impossible to audit. Under pressure, shortcuts become the norm, and technical debt deepens.

Active Directory: The heart—and vulnerable core—of technical debt

Active Directory (AD) sits at the heart of enterprise identity and access, and it’s also one of the biggest sources of hidden technical debt. What starts as business-driven decisions or boardroom pressure often snowballs into sprawling AD environments that quietly amplify risk.

• Ghost service accounts with Domain Admin rights linger from past projects or shadow IT setups, often undocumented and dangerously overprivileged.
• Old authentication protocols like NTLMv1 and unsecured LDAP stick around because legacy apps demand them, leaving credentials exposed to interception and pass-the-hash attacks.
• Fragmented forests and domains, a byproduct of mergers and global expansion, create weak trust relationships that attackers can exploit across boundaries.
• GPO sprawl from compliance-driven quick fixes leads to overlapping policies that dilute enforcement and confuse teams.
• Privileged accounts with weak or shared passwords remain under the radar, making lateral movement and full compromise far too easy.

Modernization experts agree: Cleaning up AD debt through service account inventories, privilege audits, and protocol upgrades can dramatically reduce exposure. But most organizations struggle to act. Years of underinvestment, unclear ownership, and the sheer complexity of AD environments make it hard to know where to start.

A 2025 analysis from Dark Reading underscores the urgency: Even after 25 years, AD remains a top target for attackers. Forgotten accounts, unpatched vulnerabilities, and outdated protocols are still common—and still dangerous.

Technical debt from service accounts

Service accounts are foundational to enterprise IT ecosystems, enabling seamless interactions between applications, databases, and infrastructure without human intervention. Unlike user accounts, they often possess elevated privileges, such as Domain Admin rights or access to sensitive APIs, making them prime targets for exploitation. In a typical Fortune 500 environment, thousands of service accounts might exist, many undocumented and overprivileged due to historical configurations.

Service accounts are often the quiet culprits behind persistent access risks. Many still rely on static credentials—unchanging passwords that, once compromised, give attackers a long-term foothold. In AD environments, attackers can exploit service principal names (SPNs) through Kerberoasting: requesting Ticket Granting Tickets and cracking them offline to extract credentials. It’s a well-known technique but still surprisingly effective, especially in hybrid setups.

As organizations bridge on-premises AD with Microsoft Entra ID or AWS IAM, misconfigurations creep in. Overly permissive roles, forgotten connectors, and legacy service accounts create blind spots that attackers love. And underneath it all, outdated protocols still linger.

NTLM, a relic from the 1990s, is one of the biggest offenders. Many service accounts still authenticate using NTLM, which lacks modern encryption and opens the door to manipulator-in-the-middle and relay attacks. In environments where Windows Server 2008 remnants remain, NTLM fallback mechanisms persist, allowing attackers to force downgrade scenarios when Kerberos fails and quietly slip through.

The 2025 Verizon Data Breach Investigations Report shows that stolen credentials facilitate 88% of basic web app attacks, with service accounts often exploited for lateral movement and privilege escalation. And according to the ORCA- 2024 State of Cloud Security Report, 61 % of organizations have a root user or account owner without MFA.

• Lack of centralized management: Different teams create service accounts ad hoc, resulting in identity sprawl with many undocumented and excessive privilege accounts.
• Hard-coded credentials: Developers embedding credentials in code make rotation difficult and expose systems to attackers if code is compromised.
• Overprivileged access: To avoid troubleshooting permissions, accounts are often granted excessive rights, violating least-privilege principles.

Example: A global IT consulting firm, Acuity, rapidly expanded its cloud services division through a series of acquisitions. To integrate the acquired companies' applications quickly, the DevOps team created a single service account, svc_acuity_unified, with Domain Admin privileges. The justification was that this high level of access would eliminate permissions issues when deploying code and managing infrastructure across the new, disparate AD forests. This account was hard-coded into hundreds of CI/CD scripts and legacy automation tools.

Accumulation: The account became a "ghost" identity, overlooked and undocumented as teams moved on. An attacker, after compromising a low-privilege user account via a phishing attack, used AD enumeration tools to discover this highly privileged service account. They then exploited a Kerberoasting vulnerability to crack the service account's weak, unrotated password offline. With the stolen credentials, the attacker achieved a full domain compromise, pivoting from the original low-privilege entry point to total control of the network. This allowed them to exfiltrate intellectual property and client data, leading to a major data breach and significant reputational damage.

CISO directives

• Establish a centralized service account governance framework:
  • Mandate a formal policy for the creation, life cycle management, and deprovisioning of all orphaned and unnecessary service accounts.
  • Implement a centralized inventory system for all service accounts, documenting their purpose, associated applications, and privilege levels.
• Enforce the principle of least privilege:
  • Conduct a full audit of all existing service accounts to identify and remove excessive privileges, particularly Domain Admin rights.
  • Require a formal review and approval process for all requests for elevated service account permissions.
• Secure service account credentials:
  • Transition all service accounts from static passwords to a managed credential system, such as a privileged access management (PAM) solution.
  • Implement an automated process for password rotation and mandate the use of long, complex passwords for any service accounts not yet integrated into a PAM system.
  • Actively monitor for and remediate Kerberoasting vulnerabilities by identifying and securing service accounts with weak or unrotated SPN passwords.

Technical debt from legacy authentication protocols

Old protocols like NTLMv1 and unsecured LDAP were quick fixes from years ago when uptime mattered more than security. Built for trusted networks, they’re still used in complex AD and hybrid cloud setups. They expose credentials to easy attacks like pass-the-hash or manipulator-in-the-middle, bypassing MFA and modern defenses. Often ignored, they quietly enable breaches until it’s too late.

The same Verizon report discussed in the previous section found that 20% of breaches started with exploited vulnerabilities and a significant portion traced back to legacy authentication. Not flashy zero-days—just old code, still running, still trusted, still dangerous.

Example: Innovate Global, a software development and cloud services company, rushed to acquire a data analytics firm that used a custom-built, on-premises data warehouse. The warehouse’s core application was built in the 1990s and used NTLMv1 for all its internal communication and authentication with its local AD. To integrate the data, Innovate Global’s engineers configured a synchronization server with an NTLM fallback mechanism, ensuring the legacy app could continue to function.

Accumulation: This created a critical security hole. During a routine penetration test, a red team member gained a foothold on a server with network visibility. They used a tool like Responder to perform a pass-the-hash attack, relaying the NTLM hash of a privileged service account from the synchronization server to a domain controller. This attack succeeded because NTLMv1 lacks modern cryptographic protections, allowing the attacker to authenticate as the privileged account without ever knowing its password. They were then able to create a new, persistent backdoor account, allowing them to remain in the network undetected for months.

CISO directives

• Audit and disable outdated protocols:
  • Conduct a comprehensive audit to identify all systems and applications still using legacy authentication protocols such as NTLMv1 and unsecured LDAP.
  • Develop a phased plan to migrate these systems to modern, secure protocols (e.g., Kerberos or LDAPS with SSL/TLS).
• Enforce modern authentication policies:
  • Configure GPOs to restrict or disable NTLM fallback mechanisms and to require Kerberos authentication wherever possible.
  • Implement network monitoring to detect and alert on NTLM relay attacks and other protocol-based exploitation attempts.

Fragmented forests and domains

When companies grow through M&A, speed often wins over structure. A quick lift and shift might get systems online fast, but it leaves behind a trail of fragmented identity environments—multiple AD forests stitched together with fragile trust relationships and inconsistent policies.

It’s not just messy. It’s dangerous.

Each legacy domain becomes a potential entry point. Security policies vary. User life cycle management becomes a guessing game. And attackers? They thrive in this sprawl. One compromised subsidiary can become a launchpad for lateral movement across the entire enterprise, turning a local breach into a global crisis.

This isn’t just technical debt. It’s strategic risk disguised as operational convenience.

Example: GlobalTech Solutions underwent rapid global expansion, acquiring two different European IT firms and one in Asia. Instead of a costly and complex AD forest migration, the board mandated a lift-and-shift approach, creating insecure, one-way forest trusts to allow resource sharing. The result was a fragmented, complex AD environment with three distinct forests and multiple domains, each with its own set of administrative controls and security policies.

Accumulation: The trusts between the forests were configured with broad permissions, making it easy for an attacker to move laterally. A threat actor infiltrated the least-secure Asian firm's network through a vulnerable web server. From there, they used an AD exploitation tool to identify the insecure trust relationships. By exploiting a misconfiguration in the trust, they performed a trust ticket attack to pivot to the main GlobalTech Solutions forest. This cross-forest lateral movement allowed them to access highly sensitive intellectual property, including unreleased software code and client lists, ultimately compromising the entire enterprise from an initial entry point in a single, poorly integrated subsidiary.

CISO directives

• Develop a strategic AD consolidation plan:
  • Commission a detailed assessment of all AD forests and domains resulting from M&A.
  • Create a multi-year roadmap for the consolidation of fragmented AD forests into a single, unified, and secure enterprise AD environment.
• Strengthen cross-forest security:
  • Review and reduce permissions on all forest trust relationships, moving from broad, two-way trusts to one-way, resource-specific trusts based on the principle of least privilege.
  • Implement continuous monitoring and alerting on all cross-forest authentication and access attempts to detect lateral movement.

Technical debt due to GPO sprawl

In large, complex AD environments, GPO sprawl is a direct result of ad-hoc, compliance-driven, or team-specific policy creation without a clear, centralized governance framework. Over time, this leads to a convoluted web of hundreds of GPOs that are often overlapping, redundant, and contradictory. This AD technical debt makes the environment brittle and unpredictable. A GPO designed to secure one system may inadvertently disable a security control on another, creating unseen security holes that attackers can exploit. This lack of a coherent security baseline not only complicates troubleshooting but also dramatically increases the attack surface. Statistics show that 40% of large organizations experience policy conflicts due to improperly managed settings.

Example: A large IT managed services provider, SecureNet, had an AD environment that grew organically over a decade. Each time a new compliance requirement (e.g., the PCI DSS or HIPAA) or security mandate was introduced, a new GPO was created. Over time, this led to hundreds of GPOs with overlapping and contradictory settings, a classic case of GPO sprawl. One GPO required complex passwords, while another, older one was configured with a weak password policy. Similarly, one policy mandated local firewall rules, while another, more recent one, turned them off for specific server groups.

Accumulation: An administrator accidentally linked the contradictory password policy GPO to an organizational unit (OU) containing all privileged service accounts. This immediately lowered the password complexity requirements for those accounts without any alerts. An attacker, leveraging a compromised user account, brute-forced the password of a privileged service account within this OU. The attack succeeded because the GPO sprawl had created a security vulnerability that was invisible to traditional monitoring tools. The attacker then used this compromised account to gain a foothold on a critical production server, leading to a service outage and data exposure.

CISO directives

• Implement a GPO governance framework:
  • Establish a formal, documented process for the creation, modification, and linking of GPOs, with a clear chain of approval.
  • Require all new GPOs to be tested in a non-production environment before deployment.
• Initiate GPO cleanup and consolidation:
  • Conduct a comprehensive audit of all existing GPOs to identify redundant, contradictory, or unlinked policies.
  • Develop a project to consolidate and simplify GPOs to reduce sprawl; improve manageability, and create a single, consistent security baseline for all systems.

Technical debt due to unsecured privileged accounts

Unsecured privileged accounts represent one of the most significant forms of AD technical debt. These are accounts with elevated permissions, like those for system administrators or application owners, that are left with weak, shared, or unrotated passwords. The root cause is often a lack of oversight and a business culture that prioritizes convenience over security, allowing for dangerous practices like password sharing and a failure to enforce the principle of least privilege. The same Verizon Data Breach Investigations Report shows that stolen credentials were the primary initial access vector in 22% of breaches, a statistic that underscores the critical danger posed by poorly managed privileged accounts. Attackers actively seek out these accounts to gain a quick and definitive foothold to perform lateral movement and exfiltrate data, transforming a minor intrusion into a catastrophic breach.

Example: In a SaaS company, CloudSync, the IT team created several high-privilege accounts for administrators and developers. Due to a culture of convenience over security, passwords were not regularly rotated or were shared among a small team of engineers to simplify access. The svc_sa_cloudadmin account, which had control over the entire cloud infrastructure, was managed with a single, unrotated password stored in a shared, unencrypted document on a network drive.

Accumulation: A departing employee who had access to the shared document used the credentials to log in to the company's network from home after their final day. Using the svc_sa_cloudadmin account, they accessed critical production servers, deleted client databases, and encrypted key files, causing a complete disruption to the company’s services for over 48 hours. The attack was not a sophisticated hack but a direct result of an unsecured privileged account, a form of technical debt that accumulated due to poor security practices and a lack of oversight.

CISO directives

• Implement a PAM solution:
  • Deploy a dedicated PAM solution to centralize the management of all privileged accounts (e.g., domain admins, local administrators, and the svc_sa_cloudadmin account).
  • Enforce a Zero Trust model for privileged access, requiring just-in-time (JIT) access and MFA for all administrative actions.
• Eliminate shared and unsecured credentials:
  • Conduct an immediate sweep to identify and eliminate all shared privileged accounts.
  • Mandate the use of unique, complex passwords for all privileged accounts and enforce automated password rotation at least every 30 days.
• Enhance monitoring and alerting:
  • Implement dedicated monitoring to track all privileged account activity in real time.
  • Configure alerts for suspicious behaviors, such as logins from unusual locations, failed login attempts, and access to sensitive resources.

Other contributors to technical debt Third-party risk and supply chain dependencies

Third-party integrations and inherited software from vendors or M&A activity are now frequent sources of technical debt and cyber exposure. CISOs often find that supply chain connections, like unmanaged APIs, legacy partner VPNs, or externally administered service accounts, are overlooked during initial integration but gradually accrue risk as business ecosystems evolve. For example, a FinTech company using a legacy payment processor may inherit service accounts with excessive privileges or API integrations using outdated TLS, exposing core financial databases.

Cloud modernization and identity debt

The rush toward cloud and hybrid infrastructure introduces a specific form of technical debt known as identity debt, consisting of forgotten, misconfigured, or overprivileged cloud service accounts, federated identities, and tokens. Rapid migration projects, often board-mandated, yield large numbers of cloud service principals and API keys that outlive their purpose, are rarely rotated, and often possess excessive permissions, making cloud environments both agile and vulnerable.

Directives for CISOs

• Cloud IAM hygiene: Perform regular audits using cloud-native tools (e.g., AWS IAM Access Analyzer or Microsoft Entra Privileged Identity Management) to flag orphaned, unused, or legacy service principals.
• Life cycle governance: Integrate service account creation and decommissioning with ITSM workflows, ensuring that every account’s existence is justified, documented, and regularly recertified.
• JIT access and automated remediation: Adopt policies enforcing JIT access for high-risk privileges, leveraging PAM and cloud secrets management to rotate keys and credentials automatically. Use cloud security posture management tools to report and remediate risky configurations directly tied to board growth mandates.

Modernizing identity management in the cloud reduces risk exposure and protects enterprise innovation initiatives often greenlit by top leadership but poorly resourced for security.

Security culture and behavioral change

Legacy technical debt isn’t just about outdated systems; it’s a reflection of how an organization operates. When business units chase short-term wins and frontline teams aren’t empowered to think long term, risky decisions slip through the cracks. Security exceptions, shadow IT, and sloppy development practices often start as quick fixes—maybe a boardroom directive or a local work-around—but they don’t stay contained. Over time, those one-offs turn into systemic vulnerabilities that are tough to unwind.

Directives for CISOs

• Tailored security awareness campaigns: Design role-based training for developers, business leaders, and IT admins that shows how technical debt impacts core business outcomes like uptime, compliance, and reputation.
• Security champions program: Establish peer-nominated champions in each business unit who are empowered to escalate risks, challenge risky work-arounds, and promote remediation as part of business process improvement.
• Gamification and incentivized remediation: Use score cards and rewards to encourage teams to reduce privileged account counts, migrate away from legacy protocols, and participate in vulnerability remediation sprints.

Embedding security into the enterprise’s operating culture shrinks technical debt long term while enabling business-driven innovation.

How to manage technical debt as a CISO

Quantifying technical debt and ROI for boards

Boards and executive committees often lack practical visibility into how technical debt translates into business risk until after a breach or audit failure. CISOs who quantify debt and frame remediation as an investment rather than a cost are more likely to win funding and support.

Directives for CISOs

• Risk dashboards: Build executive-facing dashboards that track metrics like the number of overprivileged accounts, the proportion of network traffic on legacy protocols, and the average age of service accounts, directly illustrating debt accumulation.
• Scenario analysis: Use incident simulations or recent breach data to model post-event costs (e.g., compliance fines, customer attrition, or downtime) versus the investment required to remediate technical debt, presenting clear ROI arguments.
• Alignment with business goals: Tie debt reduction projects to board priorities—resilience, digital transformation, and regulatory compliance—showing how proactive debt management underpins each.

The move from reactive reporting to proactive, metric-driven advocacy positions CISOs as strategic contributors to enterprise value and risk reduction.

Regulatory synergy and future-proofing

New regulatory frameworks in 2025 (e.g., DORA, NIS2, CCPA, and GDPR updates) increasingly hold boards accountable for unmanaged technical debt and legacy infrastructure risks in critical sectors. Deferred remediation can result in exponential fines, operational halts, and reputational damage. Directives for CISOs

• Comprehensive compliance mapping: Systematically map technical debt reduction projects to relevant regulatory requirements, reducing repetitive audit and remediation efforts.
• Board-level policy advocacy: Equip boards with analyses of how technical debt introduces compliance risk, and advocate for explicit policies that treat remediation as a KPI for business continuity, not just IT hygiene.
• Interim and long-term controls: Where migration away from legacy protocols is costly, implement compensating controls like network microsegmentation, IPS rules, and extra monitoring as stopgaps.

Using regulatory pressure as a lever, CISOs can secure sustained investment in modernization even amid fiscal constraints.

Emerging tech and automation

Automation and AI create new opportunities for CISOs to systematically identify and remediate technical debt, reducing manual oversight and accelerating risk reduction. As attack surfaces multiply, scalable tools become mandatory.

Directives for CISOs

• AI-driven risk analytics: Deploy machine learning tools to analyze authentication patterns, privilege escalations, and legacy protocol usage, predicting and prioritizing emerging legacy risk hotspots.
• Automated privileged account management: Integrate platforms that continuously discover, rotate, and decommission unused service accounts and legacy tokens, shrinking the window for exploitation.
• Continuous attestation: Use automated workflows for regular recertification of access rights, expiration of credentials, and compliance testing against live environments.

Automation allows CISOs to set and enforce controls at scale, freeing security staff to focus on strategic planning and board communication.

In the modern enterprise, Active Directory technical debt isn’t just an IT inefficiency—it’s an operational and regulatory liability. Unsecured privileged accounts, orphaned identities, and legacy access patterns quietly erode trust and resilience until they culminate in major breaches or compliance failures. CISOs who treat technical debt as measurable risk, aligning remediation with business continuity and board priorities, transform debt reduction into a strategic advantage. By embedding automation, governance, and a culture of accountability, organizations can modernize securely and future-proof their identity foundations against the next wave of cyber and regulatory challenges.

Related solutions