Category Archives: Security

SharePoint Sites Lookup

That’s a very common problem in SharePoint world. You are looking for a site owner but there is no tool available for regular user to find who owns the site.

Scenarios.

You get a link to some SharePoint site, but you do not have access to it. You requested access but nobody has responded. You need to find who is the site owner.

(To be continued)

Microsoft Form Blocked due to Potential Phishing

You are seeing messages “This form can’t be distributed as it is asking for personal or sensitive information. Contact your admin for assistance. Terms of use”

This form can’t be distributed as it is asking for personal or sensitive information. Contact your admin for assistance. Terms of use

or

Form can no longer be accessed. This form has been flagged for potential phishing. Technical details

“Form can no longer be accessed. This form has been flagged for potential phishing. Technical details”

Cause

The reason is: Microsoft enabled automated machine reviews to proactively detect the malicious collection of sensitive data in forms and temporary block those forms from collecting responses. More about it.

Solution

Ask your tenant global or security admin to go to the Microsoft Security Administration (Defender) Alerts:

Microsoft Defender Alert Phishing Form

If your list of alerts is too big – use filter by Policy: “Form blocked due to potential phishing attempt”.

Microsoft Purview - Compliance-Alerts-Filter-By-Policy

To unblock the form or confirm it is phishing – admin should open the alert:

Microsoft Defender Alert Phishing Review this Form

And then click “Review this form“.
“Review the form” opens the page “https://forms.office.com/Pages/AdminPhishingReviewPage.aspx?id=”
where is the form Id.

Then global/security admin can review the form and unblock it or confirm it is phishing:

m365 global/security admin can review the form and unblock it or confirm it is phishing

References

Adaptive scopes Retention Policies Data Lifecycle Purview

Microsoft recently implemented “Adaptive” retention policies. At step 2 of “Create retention policy” you’ll be asked “Choose the type of retention policy to create”: “A policy can be adaptive or static. Advantage of an adaptive policy will automatically update where it’s applied based on attributes or properties you’ll define. A static policy is applied to content in a fixed set of locations and must be manually updated if those locations change.”

And if you selected “Adaptive” – on the next step you will need to provide the adaptive scope (so at this moment you should already have created your adaptive scopes):

So, let us create your adaptive scopes.
What type of scope do you want to create? SharePoint sites…

And then you’ll have nothing more then set of conditions:

where you can use objects: “Site Url”, “Site Name” and “Refinable String 0″..”Refinable String 99”. Conditions would be “is equal to”, “is not equal to”, “starts with” and “not starts with”. Or you can select “Advanced query builder” and enter KQL query.

Advanced query builder

Advanced query builder allows us to use more site properties then “Site Url”, “Site Name” and “Refinable Strings” and more conditions than “is (not) equal to” and “(not) starts with”.

E.g. we can use “Title”, “Created”, “Modified” site properties and “=”,”:”,”<“, “>”, “<=”, “>=” conditions.

Working queries examples:

created>=2022-07-21
created>12/31/2021 AND modified>=7/31/2022
title:test
SiteTitle:test
RefinableString09:Test*

Not working queries examples:

site:https://contoso.sharepoint.com/sites/test* 
RefinableString11 = Birds # (do not use spaces in advanced query)
Path:https://contoso-my.sharepoint.com
Template:STS
Template:"SITEPAGEPUBLISHING#0"
Template:SITEPAGEPUBLISHING*

Query against custom site property (aka property bag value)

You can create custom site property and assign value to the property with
Set-PnPAdaptiveScopeProperty or Set-PnPPropertyBagValue.
Property must be with “Indexed” parameter. Once the property is set up, m365 search crawls site and creates crawled property. Then you map crawled property to some pre-created refinable string managed property. You can assign alias to this managed property.

In my test scenario I used RefinableString09 with alias SiteCustomSubject.

Site property valueQueryresult
BirdingRefinableString09:Birddoes not work
BirdingSiteCustomSubject:Birddoes not work
BirdingRefinableString09:Bird*works
BirdingSiteCustomSubject:Bird*does not work
BirdingRefinableString09:Birdingworks
BirdingSiteCustomSubject:Birdingdoes not work
BirdingRefinableString09:Birding*works
BirdingRefinableString09=Birding
BirdingRefinableString09=Bird.
BirdingRefinableString09=Bird*.
BirdingSiteCustomSubject=Birding.

Query against multi-value property.

Site property valueQueryresult
TestA TestBRefinableString09:TestAworks
TestA TestBRefinableString09 = ‘TestA TestB’does not work
TestA TestB??? RefinableString09=’Test10 Test5′does not work
TestA TestBRefinableString09:TestB ?
TestA,TestBRefinableString09:Test*works
TestA,TestBRefinableString09=Test*does not work
TestA,TestBRefinableString09:Testdoes not work
RefinableString09=TestA.
TestA,TestB(basic) RefinableString09 starts with testworks

What is the takeaway from this for SharePoint administrators? We would be asked to configure SharePoint the way compliance/retention people can use Refinable Strings.

External Access Guest Access Microsoft 365 SharePoint Teams

(WIP)

Will be saving gotchas on Microsoft 365 External Access and Guest Access in SharePoint and Teams

We configure external/guest access in AAD, m365 Admin Center, Teams Admin Center, SharePoint Admin Center, specific Group, Team or SharePoint site.

We can configure external guest access directly, or can configure sensitivity labels and policies in Purview (Compliance Admin Center). Configuring sensitivity labels for sites/groups we configure external guest access settings. Configuring sensitivity labels policies we apply labels.

Sensitivity labels in Microsoft Teams, Microsoft 365 groups, and SharePoint sites

  1. Follow instructions in MS article:
  2. beware that “Connect-AzureAD” works only in Windows .net framework – i.e. PowerShell 5.1
    if you try to run it in PowerShell 7 – you can get “Connect-AzureAD: One or more errors occurred. (Could not load type ‘System.Security.Cryptography.SHA256Cng’ from assembly ‘System.Core, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089’.)” Error.
    (check Connect-AzureAD Could not load type ‘System.Security.Cryptography.SHA256Cng’ from assembly)

Configuring Sensitivity Labels

Sensitivity labels are configured under Microsoft Purview (Compliance Center), Solutions, Information Protection. You’d need a global admin or “Compliance Administrator” or “Azure Information Protection Administrator” (?) role:

Since we are talking sensitivity labels for SharePoint Sites (not documents), we define label scope as “Groups and Sites”: “Configure privacy, access control, and other settings to protect labeled Teams, Microsoft 365 Groups, and SharePoint sites.”

Then we define which protection settings for groups and sites we should configure on the next steps:
– Privacy and external user access settings – Control the level of access that internal and external users will have to labeled teams and Microsoft 365 Groups.
– External sharing and conditional access settings – Control external sharing and configure Conditional Access settings to protect labeled SharePoint sites.

If we selected previously “Privacy and external user access settings” – now we need to select group/team privacy (These options apply to all Microsoft 365 Groups and teams, but not standalone sites). When applied, these settings will replace any existing privacy settings for the team or group. If the label is removed, users can change privacy settings again. You can also allow external user access – if group owner will be able to add guests:

Next step – define external sharing and conditional access settings. Specifically, if the content of the SharePoint site can be shared with Anyone (anonymously) or with authenticated users (new or existing) or no external sharing is allowed:

And you can either control the level of access users have from unmanaged devices or select an existing authentication context to enforce restrictions:

Configuring sensitivity labels policies

Sensitivity label policy is basically which label should be available to apply for what users and some other settings like
– do users need to provide justification before removing a label or replacing it with one that has a lower-order number or
– will users be required to apply labels and optionall the default label

View existing sensitivity labels

“Global reader” role allows view existing sensitivity labels configuration:

Wording would be a little different, but all aspects of the label configuration will be mentioned. E.g. when editing GUI says label scope is “Groups & sites”, read-only label summary defines Scope as “Site, UnifiedGroup”.

Gotchas

Applying sensitivity labels programmatically

To apply a label to a m365 group or Teams site with a group behind: MS Graph API support only Delegated permissions.

Set-PnPSiteSensitivityLabel” works in the current site context.
Description says “If the site does not have a Microsoft 365 Group behind it, it will set the label on the SharePoint Online site and will not require Microsoft Graph permissions and will work with both delegate as well as app only logins.”
In fact (7/22/2022) app permissions are not working. This cmdlet can assign label to a standalone or a group-based site only with delegated permissions.

Set-PnPTenantSite” allows you to remove or apply site sensitivity label to both standalone and group-based sites with app permissions. Furthermore, group and team settings respect this. I.e. if you apply label to a group-based site – group will pick this up.

References

Ownerless Microsoft 365 groups, teams and sites Q&As

Every team in Microsoft Teams or a Microsoft 365 group or a SharePoint site must have an owner/owners. Otherwise to whom we communicate on any question – site/group permissions, membership, site/group/team retention policy, content classification etc. Who will be responsible for team/site/group content and configuration and who will provide access to this site for other users.

MS: A team in Microsoft Teams or a Microsoft 365 group and its related services can become ownerless if an owner’s account is deleted or disabled in Microsoft 365. Groups and teams require an owner to add or remove members and change group settings.

Recently Microsoft implemented a new feature: a policy that automatically asks the most active members of an ownerless group or team if they’ll accept ownership. Very important feature. TY Microsoft!

The configuration via wizard is straightforward and intuitive.

But still we have some questions regarding the policy.

Q: Why it is important?
A: Because many other “governance” activities (e.g. permissions attestation, retention policies) rely on site/team ownership. I.e., before we notify site owner that the site is going to be deleted due to inactivity – we want an owner present.

Q: Is it about groups ownership or sites ownership?
A: Group ownership and group-based sites ownership (teams, yammer etc.). Non-group based aka Standalone sites (e.g. communication) are not in scope of this feature/policy.

Q: Who can configure this policy? What kind of permissions required to create/update policy?
A: Microsoft says “Manage Microsoft 365 groups” permissions required – e.g. admins with Global admin or Groups Admin roles required. “Teams administrator” or “SharePoint Administrator” cannot configure the policy.

Q: How about group with no members? What if somebody created a group but did not add any members?
A: Assuming somebody created a group and left company. In this the policy will not work – as there is nobody who can be a new owner. This kind of groups must be handled manually, as no owners no members does not mean nobody uses related SharePoint site.

Q: How do we know the group is ownerless? Only if owner has been deleted from AAD? What if an owner is just blocked or unlicensed?
A: blocked or unlicensed users are still users; so the policy will be triggered if the group owners list is empty.

Q: We have implemented Azure AD Settings “EnableGroupCreation” and “GroupCreationAllowedGroupId” (as per Microsoft: Manage who can create Microsoft 365 Groups), so not everyone can create m365 groups. Would this impact ownerless groups policy? In other words – if a user cannot create group – would this keep user from being assigned as a group owners?
A: No. Microsofts’ Manage who can create Microsoft 365 Groups trick regulates groups creation only. Later – when a group is created – nothing prevents such user to be added as a group owner.

Q: I support a large Microsoft 365 environment and we already have hundreds of ownerless groups. I’m concerned how users might react and whether our helpdesk support teams are ready for new type of tickets etc. Implementing the policy in test/stage environment does not make much sense, since there are no really active users etc. So, can I test this policy in production – on real users, but pilot it within a small number of users or ownerless groups before applying to all groups in the environment.
A: Yes, you can do a test or pilot implementation in production limiting the impacted users or groups.
– if you need to limit users who will be getting notifications a “pilot team” – during Step 1 “Notification Options” under “Specify who can receive ownership notifications” you can select “Allow only certain active members” and under “Specify security groups to ‎allow members‎” you can select a security group – so only members from the specified security group will be sent ownership request. Microsoft 365 groups do not work here.

NB: But there is a bug (I believe): When you specify this option (Allow only certain active members and a security group) – the policy just does not work.

another option – you can test the policy on a several selected m365 groups:

Q: I know the policy is applied to Microsoft 365 groups only. But I have many standalone sites with no owners (no site collection administrators). How do I deal with ownerless SharePoint sites?
A: How about converting standalone sites to Microsoft 365 group-based sites (TBC)?

Q: What happens to group that become ownerless after the policy is created?
A: The policy will be triggered against this group – so next day the most active group members will receive invitation.

Q: What happens if several of the notified members accepts the ownership request?
A: Two first served basis. As per Microsoft, only two members can be assigned to group owners via the policy. When a group got two owners – invitation message actionable item for the rest will be converted from “Would you like to be a group owner?” to “MemberName1 and MemberName2 have already agreed to become group owners.” with no “Yes” and “No” buttons.

Track the ownerless group policy in action via Audit Log

How do I, as an Microsoft 365 administrator, know if the policy works or not, are the emails sent or not and how many (if any) users are accepted “Would you like to be a group owner?” invitation?

Microsoft 365 Audit Search under Microsoft Purview (Compliance center) should help.

Operations:

  • OwnerlessGroupNeedAttention – “Unattended ownerless group”
  • OwnerlessGroupNotified – “Notified ownerless group”
  • OwnerlessGroupNotificationResponse – “Responded to ownerless group notification”

UserId: OwnerlessGroupComplianceAssistant

Record Type (AuditLogRecordType): 126

It seems like event is not added to the Audit log when a policy is created or updated.

Some more findings:

If a public group does not have an owner – all requests to joint the team will be declined with “The team does not have an owner” message:
(that means no new members, i.e. no new contributors, but read-only visitors access is sill available for everyone, as group is public):

Users can go to My Groups to see groups (Teams, Yammer communities and SharePoint Sites) they are members or owners of.

Proposal to be a group owner lasts forever. So if a user after some time finds an email that asks him “Would you like to be a group owner?” and clicks Yes – he/she will be a group owner, even if the policy is already updated or removed.

As per Microsoft, only first two members can accept the ownership of an ownerless group. No additional members are allowed to accept ownership. If either one or two members accept ownership, other members won’t receive further notifications.

Q: Can I customize an ownership notification?
A: Yes, but
– E-mail message body is limited to ~1040 character
– Policy does not provide any WYSIWYG rich text format, but you still can format it – headers, bold/italic, links, bullets/lists: more on email template format.

A member can forward invitation message, but recipient will not see actionable “Yes” “No” buttons.

Who can create Microsoft 365 Groups

It is possible to limit users – who can create Microsoft 365 Groups (please refer to Microsoft: Manage who can create Microsoft 365 Groups – there is a guide and PowerShell code sample). This might help to keep the environment under control – let say, “only managers can create groups”, or “contractor should not be able to create teams”.

It would be good if the configuration would be consistent in terms “if a user cannot create a group – user cannot be a group owner”. Unfortunately, with current configuration options (Aug 2022), this is not the case.
Azure AD Directory Setting “GroupCreationAllowedGroupId” works only for creation. Later, when the group is create – it is possible to add to group as a group owner those who is not able to create group.

Issues

“Ownerless group policy configuration failed” error message.
And “Failure in configuring ownerless groups policy” and “Please try again.”
– seems like a permission issue.
SharePoint admin, Teams admin or Group admin roles: cannot configure Ownerless Groups Policy.
Global admin: yes, can configure Ownerless Microsoft 365 Groups Policy.
What is the minimum role required?
According to a recent update of the Microsoft’s article – “A Global administrator can create a policy…”

References

Testing Sites.Selected SharePoint and MS Graph API

Sites.Selected MS Graph API permissions were introduced by Microsoft in March 2021. One year later, in 2022 they added SharePoint Sites.Selected API permissions.

Azure registered app with SharePoint and MS Graph API Sites.Selected permissions

Why is this so important? Because MS Graph API for SharePoint is still limited and cannot cover all possible needs. I’d estimate: 90% of applications use SharePoint CSOM, so developers have to use AppInv.aspx to provide permissions for their applications to SharePoint API.

But from this moment – having SharePoint API permissions in MS Graph – in theory – we can fully rely on permissions provided in Azure and – in theory – this should allow us disable SharePoint-Apps only principal:

Set-SPOTenant -DisableCustomAppAuthentication $true

My math professor taught me: “before trying to find a solution – ensure the solution exists.” So let us test:

Are we really able to work with a specific SharePoint site using MS Graph and SharePoint API Sites.Selected permissions provided via Microsoft Azure?

What will happen with our new/legacy applications if we disable SharePoint app-only SPNs (DisableCustomAppAuthentication)?

I’m getting controversial test results… maybe PnP.PowerShell 1.10 is not fully support SharePoint Sites.Selected API.

Tech Wizard (Sukhija Vikas) on March 20, 2022 in the article “SharePoint and Graph API APP only permissions for Selected Sites” suggests using pre-release (AllowPrerelease).

So please ignore the following for a while.

Meantime I’ll test providing SharePoint Sites.Selected API permissions via Graph API call.

(wip) Test set #1: Certificate vs Secret

DisableCustomAppAuthentication: $false (SP-app-only spns are enabled).
All applications have “write” access provided to a specific site only.
Connecting with Connect-PnPOnline and then test access with Get-PnPSite

App / Get-PnPSiteSecretCertificate
ACS based (Azure+AppInv)OKThe remote server returned an error: (401) Unauthorized.
MS Graph API Sites.SelectedThe remote server returned an error: (403) Forbidden.The remote server returned an error: (401) Unauthorized.
SharePoint API Sites.SelectedOKOK
MS Graph API + SharePoint API Sites.SelectedAccess is denied. (Exception from HRESULT: 0x80070005 (E_ACCESSDENIED))OK
App with no permissionsThe remote server returned an error: (403) ForbiddenThe remote server returned an error: (401) Unauthorized

(wip) Test set #2: Sites.Selected SharePoint vs MS Graph (secret)

  • DisableCustomAppAuthentication = $false
    (SP-app-only spns are enabled).
  • All applications have “write” access provided to a specific site only.
  • Using Client Secret (not a certificate)
  • Using PnP.PowerShell
Action/ViaSharePoint + MS Graph
Sites.Selected
“secret”
SharePoint
Sites.Selected
“secret”
MS Graph
Sites.Selected
“secret”
Connect-PnPOnlineWARNING: Connecting with Client Secret uses legacy authentication and provides limited functionality. We can for instance not execute requests towards the Microsoft Graph, which limits cmdlets related to Microsoft Teams, Microsoft Planner, Microsoft Flow and Microsoft 365 Groups.WARNING: Connecting with Client Secret uses legacy authentication and provides limited functionality. We can for instance not execute requests towards the Microsoft Graph, which limits cmdlets related to Microsoft Teams, Microsoft Planner, Microsoft Flow and Microsoft 365 Groups.WARNING: Connecting with Client Secret uses legacy authentication and provides limited functionality. We can for instance not execute requests towards the Microsoft Graph, which limits cmdlets related to Microsoft Teams, Microsoft Planner, Microsoft Flow and Microsoft 365 Groups.
Get-PnPSiteOKOKThe remote server returned an error: (403) Forbidden.
Get-PnPListOKOK
Get-PnPListItemOKOK
Set-PnPSiteAttempted to perform an unauthorized operation.
Set-PnPListAttempted to perform an unauthorized operation.
Set-PnPListItemOKOK
New-PnPListAccess is denied. (Exception from HRESULT: 0x80070005 (E_ACCESSDENIED))
Add-PnPListItemOK

(wip) Test set #3: Read vs Write vs FullControl

DisableCustomAppAuthentication = $false
(SP-app-only spns are enabled).
All applications have Sites.Selected SharePoint and MS Graph API permissions.
Using Client Secret (not a certificate)
Using PnP.PowerShell

ReadWriteFullControl
Connect-PnPOnlineWARNING: Connecting with Client Secret uses legacy authentication and provides limited functionality. We can for instance not execute requests towards the Microsoft Graph, which limits cmdlets related to Microsoft Teams, Microsoft Planner, Microsoft Flow and Microsoft 365 Groups.WARNING: Connecting with Client Secret uses legacy authentication and provides limited functionality. We can for instance not execute requests towards the Microsoft Graph, which limits cmdlets related to Microsoft Teams, Microsoft Planner, Microsoft Flow and Microsoft 365 Groups.WARNING: Connecting with Client Secret uses legacy authentication and provides limited functionality. We can for instance not execute requests towards the Microsoft Graph, which limits cmdlets related to Microsoft Teams, Microsoft Planner, Microsoft Flow and Microsoft 365 Groups.
Get-PnPSiteAccess is denied. (Exception from HRESULT: 0x80070005 (E_ACCESSDENIED))
Get-PnPListAccess is denied. (Exception from HRESULT: 0x80070005 (E_ACCESSDENIED))
Get-PnPListItem
Set-PnPSite
Set-PnPList
Set-PnPListItem
New-PnPList
Add-PnPListItem

(wip) Test set #5: Certificate vs Secret

C#, SharePoint CSOM, PnP.Framework

Findings

PnP.PowerShell Get-, Grant-, Set- and Revoke-PnPAzureADAppSitePermission cmdlets require Azure App with MS Graph Sites.FullControl.All app permissions (otherwise it says “Access denied”) and authentication via certificate (otherwise it says “This cmdlet does not work with a ACS based connection towards SharePoint.”)

The same actions – managing permissions for the client app to the specific site collections – could be done via Microsoft Graph Sites Permissions API using just secret-based authentication.

If an azure app does not have Sites.Selected API permissions configured – “Grant-PnPAzureADAppSitePermission” works as expected – no error messages – the output is normal – as if Sites.Selected API permissions were configured in the app. The same for Get-, -Set and Revoke-. Permissions provided for the app to the site are not effective though: Connect-PnPOnline works well, but all other commands – starting from Get-PnPSite – returns “The remote server returned an error: (403) Forbidden.”

If an app have no permissions to SharePoint – “Connect-PnPOnline” works ok, but “Get-PnPSite” return an error: “The remote server returned an error: (403) Forbidden.”

Set-PnPAzureADAppSitePermission gives an error message “code”:”generalException”,”message”:”General exception while processing”
if the site is not specified.

AppInv is not working?

Error: Access is denied. (Exception from HRESULT: 0x80070005 (E_ACCESSDENIED))

References

Testing environment

  • Microsoft 365 E5 Dev environment
  • PowerShell 7.2.2
  • PnP.PowerShell 1.10
  • “write” permissions to the specific sites for client apps were assigned via PnP.PowerShell

Connecting to SharePoint Online programmatically: Secret vs Certificate

Update: Sites.Selected API MS Graph permissions was introduced by Microsoft in 2021. It was a good move towards site-level development, but still developers were limited with only what MS Graph API provides for SharePoint dev.
So devs had to use AppInv.aspx at site level to provide ACS permissions to their apps to be able to use SharePoint CSOM and REST APIs.
Recently Microsoft introduced Sites.Selected SharePoint API permissions for registered Azure Apps! So now devs should be fully happy without ACS-based permissions.

Scenario

You have an application that needs access to Microsoft 365 SharePoint Online site/list/documents. Application is running without interaction with users – e.g. unattended, as daemon job.

There are two options you can authenticate to Microsoft 365 – with the secret or with the certificate. Authenticating with certificate is considered more secure.

Questions

  • What happens if SharePoint-Apps only principal is disabled
    (i.e. ‘set-spotenant -DisableCustomAppAuthentication $true’ )?
  • Why I’m getting 401 error when authenticating to SPO?
  • Why I’m getting 403 error when authenticating to SPO with secret?
  • What permissions to I need to work with SPO?

Findings

Note: we will use PowerShell 7.2 and PnP.PowerShell 1.9 to illustrate it.

Disabled SharePoint-Apps only principal

If SharePoint-Apps only principal is disabled in your tenant
(i.e. ‘Get-PnPTenant | select DisableCustomAppAuthentication’ returns $true ), then the only way you work with SPO from code is:

  • an App registered in Azure
  • API permissions provided via Azure (MS Graph, SharePoint)
  • Certificate is used

In all other cases (even your Connect-PnPOnline command complete successfully) – you will be getting error 401 (unauthorized) when trying Get-PnPTenant or Get-PnPTenantSite or Get-PnPSite

Enabled SharePoint-Apps only principal

If SharePoint-Apps only principals are enabled in your tenant
(i.e. ‘Get-PnPTenant | select DisableCustomAppAuthentication’ returns $false ), then you have two options to work with SPO from code:

  • Azure App with a secret (Client Id + Client Secret) and permissions to SharePoint provided via SharePoint ( AppInv.aspx )
  • Azure App with a certificate (Client Id + Certificate) and permissions provided via Azure (Microsoft Graph and/or SharePoint)

Error 401 while accessing SharePoint Online with PnP

(Get-PnPTenant, Get-PnPTenantSite)