[Full-Disclosure] iDEFENSE Security Advisory 05.26.04: 3Com OfficeConnect Remote 812 ADSL Router Telnet Protocol Denial of Service Vulnerability
To: <email@example.com> Date: Wed, 26 May 2004 12:01:03 -0400
iDEFENSE Security Advisory 05.26.04
May 26, 2004
The 3Com OfficeConnect Remote 812 ADSL Router is a standalone
bridge/router, with interfaces to a Local Area Network and an ADSL
interface to a Wide Area Network.
Remote exploitation of a buffer overflow in firmware release 126.96.36.199 of
3Com's OfficeConnect Remote 812 ADSL Router could allow a denial of
By sending a specially formed long string to the telnet port of a
vulnerable device containing Telnet escape sequences, it is possible to
get it to either reboot or stop handling packets. If the device does not
reboot spontaneously, it will require a manual reboot before continuing
Successful exploitation allows an attacker to stop the device from
responding thereby preventing legitimate users from accessing the
More information about the 3Com OfficeConnect Remote 812 ADSL Router is
3Com OfficeConnect Remote 812 ADSL Router with the last firmware patch
available has been confirmed vulnerable.
A previously given workaround for other issues with the http interface
is available at the link shown. This shows how to configure the router
to prevent external access to the http port. By changing occurences of
port 80 into port 23, this method should also work for the telnet port.
VI. CVE INFORMATION
The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CAN-2004-0476 to this issue. This is a candidate for inclusion in
the CVE list (http://cve.mitre.org), which standardizes names for
VII. DISCLOSURE TIMELINE
02/18/04 Exploit acquired by iDEFENSE
03/08/04 iDEFENSE Clients notified
03/11/04 Initial vendor notification - no response
03/30/04 Secondary vendor notification - no response
05/26/04 Public Disclosure
Rafel Ivgi is credited with this discovery.
Get paid for vulnerability research
IX. LEGAL NOTICES
Copyright (c) 2004 iDEFENSE, Inc.
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Disclaimer: The information in the advisory is believed to be accurate
at the time of publishing based on currently available information. Use
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There are no warranties with regard to this information. Neither the
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