The Cybersecurity & Third-Party Risk Challenges Facing Law Firms in 2025

Law firms have become prime targets for cybercriminals hunting for the fastest path to high-value data. Many firms have invested in hardening their own systems – email, practice management, document repositories – but there’s still a major blind spot that’s putting them at risk: their vendor relationships.

Lawyers work with highly sensitive client information every day: healthcare records, financial details, M&A plans, IP, and more. Increasingly, that data flows through a web of third parties – cloud providers, eDiscovery platforms, IT service providers, and niche legal tech vendors. If those vendors aren’t secure, they become the easiest path of least resistance for attackers.

A minimal, “check the box” approach to third-party risk isn’t enough anymore. As cyber threats grow more sophisticated and more regulations and clients expect proof of vendor due diligence, firms that rely on ad hoc questionnaires and scattered spreadsheets are taking on more risk than they realize.

Why Law Firms Are Prime Cyber Targets

Law firms don’t just protect their own data – they’re custodians of their clients’ most sensitive information. A single successful breach can give attackers access to healthcare records, financial data, trade secrets, and case files that would normally require multiple attacks across different organizations.

From an attacker’s point of view, a law firm can be a one-stop shop.

At the same time, most firms are still concentrating their security efforts on the tools they directly control: case management, billing, and document management systems. That focus is understandable, but it leaves a gap. Vendors that move, process, or store client data often operate under less scrutiny, even though they can unlock just as much sensitive information.

When vendor security is treated as an afterthought, it effectively creates a back door into the firm’s data for attackers who know where to look.

Why Law Firms Are Especially Vulnerable to Third-Party Breaches

Organizations in every industry struggle with third-party risk. But law firms are particularly exposed.

They depend on a broad ecosystem of vendors to deliver client services efficiently – from cloud infrastructure and collaboration tools to litigation support and specialty legal technologies. Each of those vendors adds convenience and capability, but also expands the firm’s attack surface.

Yet many firms don’t have a structured, repeatable approach to evaluating and monitoring these relationships. Some vendors undergo a basic security review; others don’t. Assessments vary widely by matter, by practice group, or by which partner happens to be involved.

That inconsistency creates blind spots. It also makes it harder to answer increasingly common questions from clients and regulators about how the firm ensures that every third party with access to client data maintains appropriate controls.

The Constraint of Limited IT Resources

Most law firms operate with surprisingly lean IT departments. It’s common for a small team to be responsible for everything: keeping systems running, supporting users, maintaining infrastructure, handling incidents, and trying to stay on top of new technology needs.

Dedicated security staff are often limited or nonexistent. Even when there is a security function, that team is usually stretched thin across endpoint protection, identity management, incident response, and compliance.

In that environment, vendor security tends to lose out. IT and security teams understandably prioritize keeping the firm operational – email working, systems available, remote access stable. Vendor assessments, contract reviews, and ongoing monitoring frequently get pushed down the list, even as expectations around third-party oversight keep rising.

The result: third-party risk work becomes reactive – addressed only when a large client demands it, or when a new vendor is obviously high-risk, instead of being part of a consistent, firm-wide process.

The Burden of Partner-Funded Technology

The challenge isn’t just limited staff. Law firms also face a unique budgeting constraint: technology and security investments often come directly out of partner profits.

Unlike corporations with dedicated, centralized IT budgets, law firms typically decide on major technology spend by weighing it against compensation and distributions. That dynamic can make it harder to justify long-term security investments, especially when the risks feel abstract or the firm hasn’t yet experienced a serious incident.

Security improvements, including a more robust third-party risk program, end up competing with billable work and near-term financial goals. Even when partners recognize the importance of vendor security, other priorities frequently win.

Over time, that creates a growing gap between what clients expect – clear, documented proof of vendor due diligence – and what the firm’s current tools and processes can deliver.

The Limits of Manual Vendor Security Workflows

Given those constraints, many law firms rely on manual, patchwork processes for vendor security.

Vendor assessments might be managed via spreadsheets, shared drives, and long email threads. Questionnaires are sent one-off, often customized from scratch. Responses come back in inconsistent formats, stored in different locations, and rarely centralized in a single system of record.

Reviews themselves can drag on. Multiple stakeholders – IT, security, legal, and sometimes external counsel – need to weigh in. The process can feel as slow and formal as drafting a contract or negotiating a complex agreement.

These workflows simply don’t scale as the firm grows. As more vendors are added and more clients ask for evidence of vendor oversight, it becomes harder to keep track of who has been evaluated, what issues were found, and whether remediation ever happened.

In practical terms, vendors handling sensitive client data are sometimes treated no differently than those managing office supplies – without a clear, documented difference in the level of scrutiny applied.

The Real-World Impact of Weak TPRM

The consequences of an underpowered third-party risk program are anything but theoretical.

When a third-party incident finally hits, firms can face significant direct costs: breach investigation, remediation, outside forensics, notification, and potential legal exposure. For firms with partner-funded budgets, those costs often come directly out of profit.

The damage doesn’t stop there. Client relationships – central to every practice – can be shaken. Even if the root cause of the incident lies with a vendor, clients tend to hold their law firm accountable for protecting their data. Trust that took years to build can erode quickly.

Inside the firm, these events strain culture and morale. Partners may question leadership decisions. Already-stretched IT and security teams can feel blamed for circumstances they never had the resources to control. Careers and internal credibility can be seriously impacted, even when individuals are doing their best with limited tools.

All of this is why third-party risk management can’t remain an informal, ad hoc exercise. It needs to be a defined, repeatable part of how the firm operates.

How Perimeter Strengthens Law Firm Vendor Security

Perimeter is designed to give law firms a practical, end-to-end way to bring vendor security under control, even with a small IT or security team.

Instead of scattered spreadsheets and email threads, the platform centralizes vendor information in one secure location. Assessments, responses, documents, issues, and monitoring data are all tied back to each vendor, so you can see the full picture in a single place.

From there, Perimeter helps law firms:

• Automate assessments and follow-up.
  The platform automatically distributes questionnaires, tracks responses, and consolidates supporting documentation into a streamlined workflow. This reduces the administrative burden while making it easier to ensure that no vendor falls through the cracks.
• Prioritize risk intelligently.
  Vendors can be scored and ranked based on factors like the type of data they handle and the services they provide. A provider that touches thousands of Social Security numbers naturally gets more scrutiny than one that manages low-risk office-related services.
• Make better use of limited IT and security time.
  By standardizing and automating much of the vendor assessment process, Perimeter cuts the manual work involved in managing third-party risk. That frees your small team to focus on higher-value strategic priorities instead of chasing down questionnaires and documents.
• Show clear ROI to partners.
  A more mature third-party risk program isn’t just a cost center. It helps protect client relationships, supports the firm’s reputation, and can be a differentiator in competitive pitches – especially when clients now ask detailed questions about vendor oversight.
• Stay ready for clients and regulators.
  Perimeter makes it easier to generate audit-ready reports and evidence when clients, auditors, or regulators ask for proof of vendor due diligence. Instead of scrambling to compile materials from multiple systems, you can pull consistent, structured reporting from a centralized platform.
• Move from point-in-time to ongoing oversight.
  With real-time monitoring capabilities, the platform can alert you when a vendor’s security posture changes, new issues emerge, or risk signals rise. That allows you to address problems earlier, before they turn into costly incidents.

The goal isn’t to turn law firms into cybersecurity companies. It’s to provide a realistic, manageable way to run vendor security with the people and time you already have.

Moving Toward a Risk-Aware Legal Sector

Given the sensitivity of the data law firms handle, strong vendor security is quickly becoming a condition of doing business, not a “nice to have.”

Clients are increasingly asking detailed questions about how their outside counsel manages third-party risk. Regulators and insurers are paying closer attention as well. They want to know that every vendor with access to their data is being evaluated and monitored – not just the largest or most visible ones.

Without a structured approach to vendor security and third-party risk management, it becomes harder to win and retain these clients. It also becomes harder to give firm leadership clear, confident answers about the risks created by your vendor ecosystem.

The question isn’t whether your firm needs a better approach to vendor security. It’s how you can put a consistent, defensible program in place in a way that fits your resources and culture.

Perimeter helps law firms do exactly that: centralize vendor oversight, reduce manual effort, and build a vendor security program that’s repeatable, defensible, and right-sized for your team. If you’d like to see what that could look like for your firm, you can request a demo and explore how Perimeter supports vendor risk management across the full lifecycle.