What is Guest Access?

A serious risk in allowing guest access is the introduction of malware to SaaS environments. Employees using collaboration apps feel they are in safe zones and are more likely to inadvertently click on malicious links introduced in phishing attacks that can infect an enterprise environment.

Additionally, if guest user accounts are not subject to strong authentication practices (e.g., multi-factor authentication), they could be more vulnerable to unauthorized access from bad actors.

Guests might gain access to sensitive or confidential data that should not be shared with external parties. This can lead to data leaks or breaches.

Guests could also inadvertently expose data by sharing or mishandling it, especially if they have editing rights. Guests with write permissions might accidentally or intentionally delete or modify important data, leading to data loss.

Allowing guest access can lead to non-compliance with data protection regulations (e.g., GDPR, HIPAA) if data is shared or accessed improperly. Guest access can also complicate compliance reporting and audits.

In Slack, guest access allows organizations to invite people who are not full-time members of the workspace to collaborate on specific channels or projects. Guests have limited permissions compared to full members. They can read and post messages in their designated channels but typically don’t have the ability to manage channels, invite other users, or access workspace-wide settings.
There are two types of guest access in Slack: single channel and multi-channel guests.
Guests can only access files and messages that have been shared with them, however, it’s crucial to revoke guest access when it is no longer needed.

In Teams, guest access enables enterprises to include a person from outside the organization to a team’s space where they can chat, call, meet, and collaborate on files. A guest can be given nearly all the same Teams capabilities as a native team member.
Recently, Teams has become an expanding SaaS attack surface for phishing expeditions by external users. This attack vector exploits the default settings in Microsoft Teams, which allows external users to message other tenants’ users.
Admins can control whether to allow guest access to groups for their whole organization or for individual groups.

The “visitor sharing” option in Google Workspace lets guests, including those without a Google account, to collaborate on files and folders. Sharing can be set to anyone or only visitors from trusted domains.
Guest users can access Google Drive, Docs, Sheets, Slides. The SaaS security team should review who has access to an organization’s files and folders.
Visitors can view, comment on, suggest edits to, and edit files that are shared with them. If a visitor has edit access to a file, they can share the file with another Google user. The admin can also upgrade a visitor to a Google Workspace account to retain the visitor’s collaboration history, including document comments and edits.

Guest access in Salesforce allows unauthenticated users to view certain pages and information through an organization’s Salesforce community experience sites.
App owners need to use various settings and permissions to protect their data and customers’ data, and publicly share the site with guest users. There have been cases of Salesforce administrators erroneously giving guest users access to internal resources, which can lead to unauthorized users accessing private information and data leaks.

GitHub allows people who aren’t members of organization to access repositories, which is the primary purpose of its guest access.
Public repositories are accessible to everyone, including unauthenticated guests, while private repositories require authenticated access with explicit permission from repository owners or administrators. For public repositories, careful management of access permissions is crucial for private repositories to maintain security and privacy.

Guest Mode in Zoom enables participants to join meetings without requiring authentication. However, when the link to the meeting is shared, including in publicly visible spaces such as social media, the meeting will become completely public and anyone with the link can join it. In the event of the participation of uninvited attendees, known as Zoom bombing, a participant can be removed, and the settings should only enable the host to present.
The Waiting Room feature allows the host to admit participants individually and block unwanted guests.