[NEWS] 3Com Home Connect Cable Modem Vulnerable to Denial of Service

From: support@securiteam.com
Date: 10/01/01


From: support@securiteam.com
To: list@securiteam.com
Subject: [NEWS] 3Com Home Connect Cable Modem Vulnerable to Denial of Service
Message-Id: <20010930224236.CE05E138C2@mail.der-keiler.de>
Date: Mon,  1 Oct 2001 00:42:36 +0200 (CEST)

The following security advisory is sent to the securiteam mailing list, and can be found at the SecuriTeam web site: http://www.securiteam.com
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  3Com Home Connect Cable Modem Vulnerable to Denial of Service
------------------------------------------------------------------------

SUMMARY

Home Connect is and External cable modem manufactured by 3Com, and
distributed by numerous Cable providers.

A problem has been discovered in the cable modem firmware that could make
it possible for remote users to deny service to legitimate users of this
network hardware.

This hardware has port 80/TCP wide open for the entire network, letting
any user on the internet to access the homepage that it has in it by
default. The problem occurs when a user reaches this page, and making a
request of a file (Existing or not) of more than 100 Characters. This will
cause the modem to Reset in the best case.

DETAILS

Vulnerable systems:
3Com Home Connect Cable Modem External with USB (#3CR29223 --
DISCONTINUED)

Exploit:
The following URL will trigger the DoS:
http://target-3com-cablemodem/> (That is 100
characters)

Solution:
As a workaround for this issue, users can filter port 80 of the cable
modem. Alternatively, since this modem is discontinued (they no longer
make it) you should just call your ISP, tell them about the problem and
ask to replace the cable modem for a newer one.

ADDITIONAL INFORMATION

The information has been provided by <mailto:aharasic@terra.cl> Alex S.
Harasic.

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DISCLAIMER:
The information in this bulletin is provided "AS IS" without warranty of any kind.
In no event shall we be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages.



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