[release-10.11] MM-68547: Tighten authorization on group syncable link and patch endpoints (#36434)

Automatic Merge

server/channels/api4/group.go

@@ -377,10 +377,35 @@ func linkGroupSyncable(c *Context, w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	groupSyncable := &model.GroupSyncable{
-		GroupId:    c.Params.GroupId,
-		SyncableId: syncableID,
-		Type:       syncableType,
+	appErr = verifySchemeAdminAssignmentPermission(c, syncableType, syncableID, patch)
+	if appErr != nil {
+		appErr.Where = "Api4.linkGroupSyncable"
+		c.Err = appErr
+		return
+	}
+
+	// Upsert onto the existing row only when it is currently active so
+	// unspecified fields are preserved. A fresh link, or a re-link of a
+	// soft-deleted row, starts from a zero-value struct so that fields
+	// the caller did not (or was not authorized to) set are not carried
+	// over from the previous incarnation. The downstream upsert clears
+	// DeleteAt when re-activating.
+	existing, appErr := c.App.GetGroupSyncable(c.Params.GroupId, syncableID, syncableType)
+	if appErr != nil && appErr.StatusCode != http.StatusNotFound {
+		appErr.Where = "Api4.linkGroupSyncable"
+		c.Err = appErr
+		return
+	}
+
+	var groupSyncable *model.GroupSyncable
+	if existing != nil && existing.DeleteAt == 0 {
+		groupSyncable = existing
+	} else {
+		groupSyncable = &model.GroupSyncable{
+			GroupId:    c.Params.GroupId,
+			SyncableId: syncableID,
+			Type:       syncableType,
+		}
 	}
 	groupSyncable.Patch(patch)
 	groupSyncable, appErr = c.App.UpsertGroupSyncable(groupSyncable)
@@ -392,8 +417,9 @@ func linkGroupSyncable(c *Context, w http.ResponseWriter, r *http.Request) {
 	auditRec.AddEventResultState(groupSyncable)
 	auditRec.AddEventObjectType("group_syncable")
 
+	syncRoles := patch.SchemeAdmin != nil
 	c.App.Srv().Go(func() {
-		c.App.SyncRolesAndMembership(c.AppContext, syncableID, syncableType, c.Params.GroupId)
+		c.App.SyncRolesAndMembership(c.AppContext, syncableID, syncableType, c.Params.GroupId, syncRoles)
 	})
 
 	w.WriteHeader(http.StatusCreated)
@@ -560,6 +586,13 @@ func patchGroupSyncable(c *Context, w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	appErr = verifySchemeAdminAssignmentPermission(c, syncableType, syncableID, patch)
+	if appErr != nil {
+		appErr.Where = "Api4.patchGroupSyncable"
+		c.Err = appErr
+		return
+	}
+
 	groupSyncable, appErr := c.App.GetGroupSyncable(c.Params.GroupId, syncableID, syncableType)
 	if appErr != nil {
 		c.Err = appErr
@@ -577,8 +610,9 @@ func patchGroupSyncable(c *Context, w http.ResponseWriter, r *http.Request) {
 	auditRec.AddEventResultState(groupSyncable)
 	auditRec.AddEventObjectType("group_syncable")
 
+	syncRoles := patch.SchemeAdmin != nil
 	c.App.Srv().Go(func() {
-		c.App.SyncRolesAndMembership(c.AppContext, syncableID, syncableType, c.Params.GroupId)
+		c.App.SyncRolesAndMembership(c.AppContext, syncableID, syncableType, c.Params.GroupId, syncRoles)
 	})
 
 	b, err := json.Marshal(groupSyncable)
@@ -710,6 +744,34 @@ func verifyLinkUnlinkPermission(c *Context, syncableType model.GroupSyncableType
 	return nil
 }
 
+// verifySchemeAdminAssignmentPermission requires the caller to hold the
+// role-management permission for the target syncable
+// (manage_team_roles / manage_channel_roles), or the sysconsole groups
+// write permission, before an explicit SchemeAdmin value in the patch is
+// accepted. A nil patch.SchemeAdmin is a no-op.
+func verifySchemeAdminAssignmentPermission(c *Context, syncableType model.GroupSyncableType, syncableID string, patch *model.GroupSyncablePatch) *model.AppError {
+	if patch == nil || patch.SchemeAdmin == nil {
+		return nil
+	}
+
+	if c.App.SessionHasPermissionTo(*c.AppContext.Session(), model.PermissionSysconsoleWriteUserManagementGroups) {
+		return nil
+	}
+
+	switch syncableType {
+	case model.GroupSyncableTypeTeam:
+		if !c.App.SessionHasPermissionToTeam(*c.AppContext.Session(), syncableID, model.PermissionManageTeamRoles) {
+			return model.MakePermissionError(c.AppContext.Session(), []*model.Permission{model.PermissionManageTeamRoles})
+		}
+	case model.GroupSyncableTypeChannel:
+		if ok, _ := c.App.SessionHasPermissionToChannel(c.AppContext, *c.AppContext.Session(), syncableID, model.PermissionManageChannelRoles); !ok {
+			return model.MakePermissionError(c.AppContext.Session(), []*model.Permission{model.PermissionManageChannelRoles})
+		}
+	}
+
+	return nil
+}
+
 func getGroupMembers(c *Context, w http.ResponseWriter, r *http.Request) {
 	permissionErr := requireLicense(c)
 	if permissionErr != nil {