NTA Monitor

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New version of network scanning tool arp-scan released

15th March 2011 A new version of a respected and popular network scanning tool has been released. Read More

Tests show rise in number of vulnerabilities affecting web applications with SQL Injection and XSS most common flaws

1st March 2011 SQL injection and cross-site scripting (XSS) were the most common flaws found in web applications in 2010 according to results from tests carried out by NTA Monitor. Read More

Assess risk to manage effects of budget cuts

9th February 2011 Signs of economic recovery may be appearing in some industries, but for most organisations - particularly in the public sector - budget cuts and cost savings are here to stay for the foreseeable future. Read More

"Basic security threats not changed in 15 years"

1st February 2011 There may have been significant technological advances to the hardware and software organisations use, but according to Roy Hills, who co-founded NTA Monitor in 1996, the basic security threats have not changed in the last 15 years. Read More

Borderware Firewall Flaw

NTA Monitor, Internet security testing specialists, through routinely testing large numbers of corporate customer sites, have discovered a flaw in the design of Borderware, which means it is vulnerable to TCP/IP session spoofing.

Borderware, a firewall product of some years pedigree and a market share of about 10%, formerly a product of Secure Computing Inc, has recently become a product of Borderware Technologies Inc.

In the UK the product has been used by numbers of health organisations in the NHS, and local government.

The root cause of the flaw is that the TCP/IP stack in the product allocates initial TCP sequence numbers in a non-random, predictable manner.

The vulnerability is not trivial to exploit, but where IP addressing is used as part of an authentication scheme the implications could be serious. Simpler exploitation avenues could include untraceable 'perfect spoofing' of email.

NTA Monitor have shown that Version 5 is vulnerable; and since being informed Borderware have made their own tests and confirmed the vulnerability, which is also assumed to apply to previous versions.

Borderware have as yet made no public statement, but have said in email that the next version will address the problem.

The firewall has it's own operating system built in (a BSD Unix variant), and thus it is not possible for end-users to patch the operating system themselves.

This advisory was first released on 1st September 1998.

References

  • Security Mailing list discussions
  • NTA Monitor post and following thread on 'Bugtraq'
  • Mailing list post - Summary of emails and comments received
  • IP-spoof general references and history
  • Security Problems in the TCP/IP Protocol Suite Steve Bellovin, 1989, (compressed PostScript)
  • A Weakness in the 4.2BSD UNIX TCP/IP software Robert Morris, 1985, (compressed PostScript)
  • Steve Bellovin's description of TCP SEQ attacks
  • Details of how Kevin Mitnick used TCP SEQ attack
  • 1995 CERT Advisory CA-95:01
  • IP-Spoofing attacks reported
  • 1996 CERT Advisory CA-96:21
  • Syn flooding atacks reported
  • IP Spoofing explained (hacker article)