Cyber Risks of Document Management and Collaboration Platforms
Organizations that treat document management and collaboration platform governance as an ongoing security practice can reduce exposure, limit reconnaissance opportunities, and strengthen cyber resilience.
October is Cybersecurity Awareness Month, sponsored by the Cybersecurity and Infrastructure Security Agency and the National Cybersecurity Alliance. This annual initiative, now in its 23rd year, focuses on helping organizations and the public to enhance their awareness of cybersecurity, reduce risk, and address cyberthreats. In this article, a cybersecurity specialist explores the risks collaboration platforms introduce and details what organizations can do to impose better governance and strengthen cyber resilience.
Document management and collaboration platforms are designed for productivity, but without deliberate governance they become powerful reconnaissance tools for threat actors.
In the realm of file sharing and intranet creation, web-based document management and collaboration platforms are critical business tools that enable organizations to work as teams in shared project workspaces, coauthor documents, and keep files organized. The Microsoft SharePoint™ platform is a robust and widely used tool with easy integration into the Microsoft 365™ ecosystem. Its extensive capabilities make it highly adaptable to organizational needs, but the resulting complexity can cause critical security configurations to be overlooked. Threat actors who gain access to even a standard user account can use SharePoint software to identify employees, map organizational structures, locate sensitive repositories and business data, and prioritize future attacks. Viewing the SharePoint environment from an attacker’s perspective can help organizations identify excessive visibility and strengthen internal access controls.
The hidden visibility of the SharePoint environment
Many Microsoft 365 workloads can be deployed quickly, but the SharePoint platform requires deliberate planning and governance to align collaboration with security. In fact, more than 1,700 pages of SharePoint administrative guidance demonstrate the platform's breadth of capabilities and configuration options.
Organizations also use SharePoint tools without treating it as a stand-alone platform because files shared through Microsoft Teams™ channels are stored in the SharePoint environment, behind the scenes. As Teams adoption grows, so does the SharePoint footprint that administrators must govern. That growth often outpaces existing site governance and information access controls. At the same time, many security programs prioritize external sharing controls, which leaves internal visibility and permissions subject to default settings or inconsistent administration.
External sharing introduces an additional layer of exposure. Organizations can configure SharePoint sites and libraries to allow guests, partners, vendors, or anonymous users to access content when business needs require it. Those capabilities serve legitimate purposes, but overly permissive sharing settings can expand the audience that can discover sensitive information if they are not governed carefully. However, restricting external sharing alone does not eliminate reconnaissance opportunities because authenticated internal users often retain broad visibility across the environment.
A user account with access to a SharePoint environment can enumerate users, discover sensitive repositories, find hidden lists, and identify high-value targets within minutes. These exposures are symptoms of misconfigurations rather than a software vulnerability. While the SharePoint platform provides significant business value, its flexibility and extensive configuration options can create opportunities for information exposure. When site configurations and file permissions are taken for granted, threat actors can map an organization, identify targets, and locate sensitive data all from their browser.
Why document management and collaboration platforms enable reconnaissance
Modern document management and collaboration platforms are designed to make information easy for employees to discover, share, and access. That same emphasis on usability can also provide threat actors with efficient ways to map organizational structures, identify sensitive repositories, and prioritize future targets after compromising a user account. Exploring SharePoint use cases illustrates how architectural design and governance decisions can amplify those reconnaissance opportunities.
Before 2017, SharePoint architecture was typically hierarchical and built on a system of sites and nested subsites that inherited navigation, permissions, and designs. When Microsoft released its updated experience, it introduced a major architectural change alongside a guiding principle to explain the new design: The world is flat. Instead of requiring users to navigate deeply nested subsites, the SharePoint platform now allows organizations to create independent sites and organize them through logical groupings known as hub sites. While this change increased flexibility in the creation, relocation, and deletion of sites, it also increased the number of sites, libraries, and permissions administrators must govern. By distributing ownership across independent sites rather than centralized hierarchies, the newer platform increased the complexity of access governance and expanded the opportunities for information exposure when permissions are misconfigured.
From an attacker’s perspective, this architecture creates a reconnaissance opportunity that resembles traditional uniform resource identifier (URI) probing. The OWASP® Foundation describes URI probing as a technique for discovering resources through predictable naming conventions, identifiers, or application responses. In conventional web applications, attackers often enumerate files, directories, or user accounts by manipulating URLs and observing how the application responds. Where traditional URI probing traverses a web server’s filesystem, the SharePoint representational state transfer API exposes a similar opportunity on the logical plane. Rather than probing for files and folders, attackers can enumerate users, sites, groups, lists, libraries, and other business objects through SharePoint APIs and predictable object identifiers. The result is a detailed map of organizational structure and potential targets that can accelerate phishing campaigns and data discovery efforts.
How user profiles become target lists
Among the many objects exposed in the SharePoint environment, user account information often provides the most value to a threat actor. Knowing who works for an organization, who holds administrative rights, and how accounts are named can help attackers prioritize targets and shape more convincing phishing or credential attacks. In many environments, SharePoint settings expose this information through APIs designed to support collaboration and directory functions rather than security functions.
The following screenshot demonstrates the pattern. A compromised account begins with the profile of the currently authenticated user through the currentuser endpoint. That response often includes fields such as ID, LoginName, Email, UserPrincipalName, and IsSiteAdmin, which can reveal naming conventions, email patterns, and privileged access within the environment. From there, the same data can be retrieved for other users by changing the identifier in the request. The GetUserById() endpoint returns a single user profile, while the siteusers endpoint returns all users known to the site in one response. In this example, the following service account emails have been exposed:
- informationsecurity@[example].sharepoint.com
- infotech@[example].sharepoint.com
- techelp@[example].sharepoint.com
Site users’ endpoint
Taken together, these endpoints can expose employee accounts, administrative accounts, shared mailboxes, guest accounts, service accounts, and support addresses that might not appear in traditional organizational charts. This endpoint also reveals whether an account holds site administrator privileges, which helps threat actors identify high-value targets for phishing and credential-based attacks. What makes this exposure especially useful to attackers is that it can be exfiltrated relatively quietly in a matter of minutes.
This type of user disclosure resembles URI probing techniques. Instead of searching for files and folders, a compromised account can enumerate users and related metadata through the SharePoint API surface. Most companies do not realize that they have invested significant time and resources implementing role-based access controls within their human resources (HR) systems only to re-create a similar exposure elsewhere. Armed with this information, attackers can accelerate lateral movement, craft convincing phishing campaigns, identify privileged accounts, and confirm active accounts for credential-stuffing attempts.
Mapping sensitive repositories
After a threat actor has identified users and understands the organizational structure, the next objective is to locate valuable information. SharePoint document libraries often provide the quickest path to that goal. Specific pages can expose file inventories, folder structures, authors, and metadata that reveal far more than the documents themselves. Files with recent modification dates can expose current organizational initiatives alongside all the other files within the same folder. This information helps attackers prioritize their efforts by providing a road map of high-value repositories, sensitive business processes, and the individuals responsible for them.
The following screenshot illustrates how SharePoint document libraries can expose information that extends beyond the contents of individual files. Metadata, such as authors, creation and modification dates, location, and who has viewed the document, can all be exposed without even opening the file. Viewed together, this information can identify high-value repositories and reveal ongoing business initiatives.
Master Page Gallery list
During reviews, security teams can overlook lists because they do not look like traditional data repositories. However, lists frequently contain some of the most valuable information in a SharePoint environment. Backend processes, such as Microsoft Power Automate™ workflows, use lists as data storage and as trigger points for automation. The widespread use of SharePoint lists in business processes and automation workflows can lead to sensitive business, financial, and personally identifiable information (PII) becoming accessible to a broader audience than organizations realize. Querying specific API endpoints can reveal both visible and hidden lists along with metadata about their purpose and configuration. This information directly helps attackers prioritize their efforts by identifying where sensitive data resides and how information moves throughout the organization.
The following screenshot captures how SharePoint APIs can enumerate both visible and hidden lists within a site. The response identifies each list by name and returns metadata about its configuration that might not appear when using normal site navigation. Because many organizations use lists in Power Automate workflows, these repositories could contain operational information, financial information, or PII.
List catalog endpoint
Search as a force multiplier
When threat actors use specific pages or API endpoints, they are often confronted with thousands of documents distributed across hundreds of sites, libraries, and lists. Time is rarely on their side. Manually browsing repositories to identify valuable information is time-consuming and inefficient. SharePoint search changes that equation. By allowing users to query content across the environment, the platform dramatically reduces the effort required to discover information they already have permission to access.
For example, a user could search for terms commonly associated with sensitive business information:
- (“confidential” OR “restricted”)
- filetype:xlsx (“budget” OR “forecast”)
- (“SSN” OR ”social security”)
- (“password” OR “credentials” OR “service account”)
- (“API key” OR “client secret”)
The following screenshot demonstrates how SharePoint search can quickly identify documents that contain sensitive terms. In this example, the search query returns documents containing the phrase “API key,” allowing a user to locate potentially sensitive technical information without opening a single library.
Sensitive term search query
When sensitive repositories are broadly accessible, SharePoint search can rapidly surface customer information, financial records, employee data, security documentation, and other valuable business information. The growing use of AI further amplifies this risk. Rather than manually reviewing hundreds of search results, threat actors can use AI tools to categorize documents, identify patterns, summarize metadata, and prioritize repositories for review. Information that once required hours of manual analysis can now be ingested in minutes with barely any skill required. Threat actors do not need administrator privileges if sensitive information is already visible to ordinary users. They only need an efficient way to find it.
Prevention and mitigation
It is critical to emphasize that these exposures are not the result of a SharePoint vulnerability. In many cases, they stem from permissions and visibility settings that were never reviewed after sites, libraries, and lists were created. Organizations should periodically assess their SharePoint environments from the perspective of a standard user account. Reviewing site permissions, SharePoint groups, document libraries, lists, and search functionality can help identify information that is accessible to a wider audience than originally intended. Security teams should also evaluate lists that support Power Automate workflows and other business processes as these often contain more valuable information and garner less scrutiny than traditional documents.
The SharePoint platform provides extensive controls for limiting information exposure, but those controls require a deliberate governance strategy. Microsoft recommends managing permissions through SharePoint groups and Microsoft 365 groups rather than assigning permissions directly to individual users. Group-centric access simplifies administration, reduces stale permissions, and increases efficiency. Organizations also should periodically review custom permission levels to verify that users receive only the permissions appropriate for their roles.
One of the most effective ways to reduce unnecessary visibility is to preserve permission inheritance whenever practical. Every time inheritance is broken on a site, library, folder, or individual document, administrators create another unique permission boundary that must be maintained. Over time, these exceptions can accumulate into permission sprawl, which makes it increasingly difficult to understand who can access sensitive information. Microsoft recommends minimizing unique permission scopes because they increase administrative complexity and create opportunities for unintended access.
Organizations also can strengthen SharePoint protections by supplementing permissions with Microsoft Entra™ Conditional Access, a zero-trust policy engine. While SharePoint permissions determine which users are authorized to access, Conditional Access evaluates factors such as identity, device compliance, network location, application, and sign-in risk, before granting or continuing access. Through direct integration with the SharePoint platform, these policies can be applied to specific sensitive sites or across the organization to provide flexibility while strengthening access controls. These policies also can limit access from unmanaged devices and apply session controls that require periodic reauthentication. While these capabilities do not replace properly configured SharePoint permissions, they do add another layer of protection that can reduce the impact of a compromised account.
Site architecture also influences reconnaissance opportunities. Rather than relying on unique permissions within a single SharePoint site, organizations should separate business functions that reflect security boundaries. Keeping finance, HR, legal, and other sensitive business functions in dedicated sites simplifies permission management and reduces the possible impact of a compromised account. Even with all these recommendations implemented, the configurations will be ineffective without ongoing review. Regular reviews from the perspective of a standard user account can identify excessive visibility and reduce potential impact when an account is compromised.
Limiting reconnaissance opportunities
The SharePoint platform has become a central repository for organizational knowledge, business processes, and sensitive information. That value also makes it an attractive source of intelligence for threat actors who gain access to a user account.
Organizations that treat SharePoint governance as an ongoing security practice rather than a one-off configuration exercise can reduce unnecessary exposure, limit reconnaissance opportunities, and strengthen cyber resilience.
Microsoft, Microsoft 365, Microsoft Entra, Microsoft Teams, Power Automate, and SharePoint are trademarks of the Microsoft group of companies.
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