From Vulnerability to Visibility: What the SharePoint Attacks Reveal About the Need for Proactive Cybersecurity

The recent exploitation of Microsoft SharePoint vulnerabilities highlights a critical gap in traditional, reactive cybersecurity strategies. Learn how a proactive exposure management approach empowers federal agencies to reduce risk, streamline operations and stay secure.

Weeks ago, Microsoft disclosed four vulnerabilities affecting on-premises versions of SharePoint servers and warned about active exploit campaigns. So far, hundreds of organizations globally have been impacted, including the U.S. National Nuclear Security Administration (NNSA). Attackers include Chinese nation-state groups.

This attack highlights a growing reality: reactive cybersecurity practices are no longer sufficient in the face of today’s persistent and well-resourced adversaries.

In this blog, we’ll explore why these SharePoint vulnerabilities and attacks should serve as a wake-up call for federal agencies and how a proactive exposure management approach can help mitigate risk, increase efficiency, reduce costs and accelerate modernization initiatives. 

A persistent threat that won’t disappear with a patch

The SharePoint vulnerabilities underscore the risks of traditional, reactive security models that focus primarily on detection and response. The Chinese threat actor groups exploiting the vulnerabilities frequently use stolen credentials to establish persistent backdoors. This means that while patching a vulnerability is critical, it may not be enough. Once attackers gain access, they could maintain persistent footholds within agency environments, long after the original flaw has been addressed. On-premises servers, like the SharePoint servers affected by these vulnerabilities, are often popular targets for hackers, because organizations often set them up and then fail to regularly update them and patch their vulnerabilities. (SharePoint Online in Microsoft 365 isn’t affected.)

Look no further than the high-severity Microsoft Exchange vulnerability (CVE-2025-53786), which Microsoft disclosed last week and prompted CISA to issue Emergency Directive (ED 25-02). This elevation-of-privilege vulnerability allows attackers with administrative privileges to on-prem Exchange Servers to escalate privileges and compromise connected cloud environments.

“For on-premises software like SharePoint, which is deeply integrated into the Microsoft identity stack, there are multiple points of exposure that need to be continuously monitored in order to know, expose and close critical gaps.”

 - Robert Huber, Chief Security Officer, Tenable, speaking to Wired

The limitations of reactive security 

Historically, many agencies have relied on perimeter defense and reactive detection mechanisms to address threats after the fact. This approach leaves security blind spots, particularly in complex agency environments where on-prem, cloud, OT and identity systems intersect. 

When attackers can exploit a single vulnerability to steal credentials and navigate laterally across a network, agencies need a better way to anticipate and prioritize risk before adversaries act. Accelerating response times is key. When working with IT teams to patch hundreds of vulnerable instances, it’s critical to start with the highest risk exposures, such as those with domain privileges, external-facing systems, or assets connected to critical attack paths, then work down from critical to low exposure. This target approach ensures resources are focused where they can have the greeted impact, faster. 

Why exposure management is the path forward

A preventative approach to cybersecurity focuses on identifying and eliminating exposures before they’re exploited. This is where exposure management becomes critical. It provides visibility across your entire environment, prioritizing risk based on context and guiding action before attackers can take advantage. Just as importantly, it accelerates response times, empowering teams to move quickly by focusing first on the exposure that poses the greatest risk. 

Exposure management enables agencies to:

• Understand your attack surface: Agencies gain a holistic view of all assets including cloud, IT, OT, IoT, identities and apps.
• Pinpoint preventable risks: Because exposure management can detect vulnerabilities, misconfigurations and excessive privileges, you’ll quickly identify high risk assets.
• Accelerate response and remediation: Prioritize and address exposures that are externally facing, linked to privileged access or part of critical attack paths. This reduces dwell time and minimizes impact.
• Connect with mission goals: Group assets by business function using asset tagging and track exposure changes with cyber exposure scores.
• Shift focus from vulnerabilities to risk: Go beyond volume by understanding exploitability, asset value and business impact and mapping attack paths to critical assets.
• Understand true your risk exposure: Consolidate siloed data from multiple tools into a single platform, reducing complexity and enabling faster, more informed decisions. 

How exposure management solves key federal cybersecurity challenges

Federal agencies face a unique set of cybersecurity challenges: complex hybrid environments, aging infrastructure, siloed systems and increasing pressure to comply with evolving mandates like zero trust and Federal Information Security Management Act (FISMA) modernization. Exposure management platforms help agencies overcome these challenges by providing the following benefits.

Unified visibility across attack surfaces

Exposure management delivers a single, continuous view of all assets across IT, cloud, OT/IoT, web apps and identity systems, so agencies can eliminate blind spots and uncover hidden risks. For example, in the case of the recent SharePoint vulnerabilities, agencies can leverage external attack surface management (ASM) to discover previously unknown, internet-facing SharePoint instances that could be exposed to threat actors.

Risk-based prioritization

Agencies can shift from reactive alert fatigue to proactive risk reduction by focusing on exposures most likely to be exploited based on asset criticality, business impact and potential attack path. In the case of the SharePoint vulnerabilities, agencies can quickly isolate SharePoint assets with toxic risk combinations, such as those that are internet-facing or have excessive privileges, so teams can take immediate action instead of trying to boil the ocean.

Support for zero trust maturity

Exposure management ties asset and identity insights together to help agencies enforce zero trust principles like least privilege, continuous validation and segmentation. In the case of SharePoint, this approach could have enabled agencies to quickly pinpoint which vulnerable instances were externally accessible or had elevated domain privileges, knowledge that is critical for limiting lateral movement and enforcing access controls

Tool consolidation and cost efficiency

Instead of relying on multiple siloed tools to manage assets and vulnerabilities across the attack surface, exposure management unifies these capabilities under one platform. This reduces complexity, improves response times and cuts overhead costs. In response to the Sharepoint vulnerabilities, for example, agencies could eliminate the need to toggle between endpoint, network, cloud and identity tools so that analysts can streamline investigations and quickly identify and prioritize impacted systems.

Operational efficiency and automation

By automating asset discovery, risk prioritization and remediation workflow, exposure management allows security teams to respond quickly and effectively, even with limited resources. For example, when the SharePoint vulnerabilities emerged, agencies could have immediately surfaced affected assets, prioritize those with toxic risk combinations and initiated guided response actions, all in a single platform with centralized visibility and reporting. 

Accountability and measurable progress

To meet federal mandates and demonstrate mission aligned outcomes, agencies need clear metrics and reporting. Exposure management enables agencies to track compliance with service level agreements, visualize risk reduction over time and generate consolidated reports that span IT, cloud, identity and OT environments. In the context of SharePoint, this means standing up focused remediation initiatives with measurable impact and clearly showing progress to leadership and auditors alike. 

With an exposure management platform, federal agencies not only improve security outcomes, they simplify operations, reduce costs and accelerate strategic initiatives like zero trust and broader IT modernization.

Tenable’s FedRAMP-authorized Tenable One Exposure Management Platform gives federal agencies the visibility and insight they need to stay ahead of threats like the SharePoint vulnerability. 

Learn more:

• Tenable Research Blog: CVE-2025-5337: Frequently Asked Questions About Zero Day SharePoint Vulnerability Exploitation
• Tenable eBook: Protecting federal government infrastructure and data from cyber attacks
• Datasheet: Tenable One FedRAMP