diff --git a/Kernel/System/AuthSession.pm b/Kernel/System/AuthSession.pm
index 464b900d6fc..f54f8b6b7f5 100644
--- a/Kernel/System/AuthSession.pm
+++ b/Kernel/System/AuthSession.pm
@@ -265,7 +265,13 @@ sub RemoveSessionByUser {
             SessionID => $SessionID,
         );
 
-        next SESSIONID if $SessionData{UserLogin} ne $Param{UserLogin};
+        if (
+            defined $SessionData{UserLogin}
+            && ( $SessionData{UserLogin} ne $Param{UserLogin} )
+            )
+        {
+            next SESSIONID;
+        }
 
         $Self->{Backend}->RemoveSessionID(
             SessionID => $SessionID,
@@ -376,6 +382,34 @@ sub GetActiveSessions {
     return $Self->{Backend}->GetActiveSessions(%Param);
 }
 
+=head2 GetOrphanedSessionIDs()
+
+returns an array with orphaned session ids,
+missing user-login defines an orphaned session for now
+
+    my @Sessions = $SessionObject->GetOrphanedSessionIDs();
+
+=cut
+
+sub GetOrphanedSessionIDs {
+    my ( $Self, %Param ) = @_;
+
+    my @OrphanedSessionIDs;
+    my @SessionIDs = $Self->GetAllSessionIDs();
+    for my $SessionID (@SessionIDs) {
+
+        my %SessionData = $Self->{Backend}->GetSessionIDData(
+            SessionID => $SessionID,
+        );
+
+        if ( !defined $SessionData{UserLogin} ) {
+            push @OrphanedSessionIDs, $SessionID;
+        }
+    }
+
+    return @OrphanedSessionIDs;
+}
+
 =head2 CleanUp()
 
 clean-up of sessions in your system
diff --git a/Kernel/System/Console/Command/Maint/Session/DeleteOrphaned.pm b/Kernel/System/Console/Command/Maint/Session/DeleteOrphaned.pm
new file mode 100644
index 00000000000..3fc48c35f7c
--- /dev/null
+++ b/Kernel/System/Console/Command/Maint/Session/DeleteOrphaned.pm
@@ -0,0 +1,56 @@
+# --
+# Copyright (C) 2021 Znuny GmbH, https://znuny.org/
+# --
+# This software comes with ABSOLUTELY NO WARRANTY. For details, see
+# the enclosed file COPYING for license information (AGPL). If you
+# did not receive this file, see http://www.gnu.org/licenses/agpl.txt.
+# --
+
+package Kernel::System::Console::Command::Maint::Session::DeleteOrphaned;
+
+use strict;
+use warnings;
+use utf8;
+
+use parent qw(Kernel::System::Console::BaseCommand);
+
+our @ObjectDependencies = (
+    'Kernel::System::AuthSession',
+);
+
+sub Configure {
+    my ( $Self, %Param ) = @_;
+
+    $Self->Description('Delete orphaned sessions.');
+
+    return;
+}
+
+sub Run {
+    my ( $Self, %Param ) = @_;
+
+    my $SessionObject = $Kernel::OM->Get('Kernel::System::AuthSession');
+
+    $Self->Print("<yellow>Deleting orphaned sessions...</yellow>\n");
+
+    my @OrphanedSessions = $SessionObject->GetOrphanedSessionIDs();
+
+    for my $SessionID ( @OrphanedSessions ) {
+        my $Success = $SessionObject->RemoveSessionID(
+            SessionID => $SessionID,
+        );
+
+        if ( !$Success ) {
+            $Self->PrintError("Session $SessionID could not be deleted.");
+            return $Self->ExitCodeError();
+        }
+
+        $Self->Print("  $SessionID\n");
+    }
+
+    $Self->Print("<green>Done.</green>\n");
+
+    return $Self->ExitCodeOk();
+}
+
+1;
diff --git a/Kernel/System/Console/Command/Maint/Session/ListOrphaned.pm b/Kernel/System/Console/Command/Maint/Session/ListOrphaned.pm
new file mode 100644
index 00000000000..7f471221051
--- /dev/null
+++ b/Kernel/System/Console/Command/Maint/Session/ListOrphaned.pm
@@ -0,0 +1,47 @@
+# --
+# Copyright (C) 2021 Znuny GmbH, https://znuny.org/
+# --
+# This software comes with ABSOLUTELY NO WARRANTY. For details, see
+# the enclosed file COPYING for license information (AGPL). If you
+# did not receive this file, see http://www.gnu.org/licenses/agpl.txt.
+# --
+
+package Kernel::System::Console::Command::Maint::Session::ListOrphaned;
+
+use strict;
+use warnings;
+use utf8;
+
+use parent qw(Kernel::System::Console::BaseCommand);
+
+our @ObjectDependencies = (
+    'Kernel::System::AuthSession',
+);
+
+sub Configure {
+    my ( $Self, %Param ) = @_;
+
+    $Self->Description('List orphaned sessions.');
+
+    return;
+}
+
+sub Run {
+    my ( $Self, %Param ) = @_;
+
+    my $SessionObject = $Kernel::OM->Get('Kernel::System::AuthSession');
+
+    $Self->Print("<yellow>Listing orphaned sessions...</yellow>\n");
+
+    my @OrphanedSessions = $SessionObject->GetOrphanedSessionIDs();
+
+    for my $SessionID (@OrphanedSessions) {
+        $Self->Print("  $SessionID\n");
+    }
+
+    $Self->Print("<green>Done.</green>\n");
+
+    return $Self->ExitCodeOk();
+}
+
+1;
diff --git a/scripts/test/RemoveOrphanedSessions.t b/scripts/test/RemoveOrphanedSessions.t
new file mode 100644
index 00000000000..e944ca935b3
--- /dev/null
+++ b/scripts/test/RemoveOrphanedSessions.t
@@ -0,0 +1,100 @@
+# --
+# Copyright (C) 2021 Znuny GmbH, https://znuny.org/
+# --
+# This software comes with ABSOLUTELY NO WARRANTY. For details, see
+# the enclosed file COPYING for license information (AGPL). If you
+# did not receive this file, see http://www.gnu.org/licenses/agpl.txt.
+# --
+
+use strict;
+use warnings;
+use utf8;
+
+use vars (qw($Self));
+
+my $SessionObject = $Kernel::OM->Get('Kernel::System::AuthSession');
+my $UserObject    = $Kernel::OM->Get('Kernel::System::User');
+
+$Kernel::OM->ObjectParamAdd(
+    'Kernel::System::UnitTest::Helper' => {
+        RestoreDatabase => 1,
+    },
+);
+my $HelperObject = $Kernel::OM->Get('Kernel::System::UnitTest::Helper');
+
+# Create test users and a session for every one.
+my @TestUserLogins;
+for my $Count ( 1 .. 3 ) {
+    my ( $TestUserLogin, $TestUserID ) = $HelperObject->TestUserCreate();
+    push @TestUserLogins, $TestUserLogin;
+
+    my %UserData = $UserObject->GetUserData(
+        UserID        => $TestUserID,
+        NoOutOfOffice => 1,
+    );
+
+    my $NewSessionID = $SessionObject->CreateSessionID(
+        %UserData,
+        UserLastRequest => $Kernel::OM->Create('Kernel::System::DateTime')->ToEpoch(),
+        UserType        => 'User',
+        SessionSource   => 'AgentInterface',
+    );
+    $Self->True(
+        $NewSessionID,
+        "SessionID '$NewSessionID' is created for user '$TestUserLogin'",
+    );
+}
+
+# orphan first session
+my @SessionIDs                = $SessionObject->GetAllSessionIDs();
+my $OrphanedTestUserSessionID = $SessionIDs[0];
+
+$SessionObject->UpdateSessionID(
+    SessionID => $OrphanedTestUserSessionID,
+    Key       => 'UserLogin',
+    Value     => undef,
+);
+$Self->True(
+    $OrphanedTestUserSessionID,
+    "SessionID '$OrphanedTestUserSessionID' has been orphaned",
+);
+
+# delete orphaned session via console command method
+# ( i.e. bin/znuny.Console.pl Maint::Session::DeleteOrphaned for maintenance )
+my $CommandObject = $Kernel::OM->Get('Kernel::System::Console::Command::Maint::Session::DeleteOrphaned');
+my $ExitCode      = $CommandObject->Execute();
+
+$Self->Is(
+    $ExitCode,
+    $CommandObject->ExitCodeOk(),
+    "Orphaned session '$OrphanedTestUserSessionID' was deleted",
+);
+
+# Check for remaining sessions.
+my @RemainingSessionIDs = $SessionObject->GetAllSessionIDs();
+
+$Self->Is(
+    scalar @RemainingSessionIDs,
+    2,
+    "Ok, only one session was deleted, two remaining.",
+);
+
+# Check if orphaned session is removed.
+for my $SessionID (@RemainingSessionIDs) {
+    if ( $SessionID eq $OrphanedTestUserSessionID ) {
+        $Self->False(
+            $OrphanedTestUserSessionID,
+            "Orphaned session: '$OrphanedTestUserSessionID' was not deleted",
+        );
+    }
+    else {
+        $Self->True(
+            $SessionID,
+            "Session '$SessionID' is found",
+        );
+    }
+}
+
+# Restore to the previous state is done by RestoreDatabase.
+
+1;