¡ª Researchers found a serious security flaw that left
core Internet technology vulnerable to hackers, prompting
a secretive effort by international governments and
industry experts in recent weeks to prevent global
disruptions of Web surfing, e-mails and instant messages.
Experts said the flaw, disclosed Tuesday by the British
government, affects the underlying technology for nearly
all Internet traffic. Left unaddressed, they said, it
could allow hackers to knock computers off-line and
broadly disrupt vital traffic-directing devices, called
routers, which co-ordinate the flow of data among distant
groups of computers.
"Exploitation of this vulnerability could have
affected the glue that holds the Internet together,"
said Roger Cumming, director for England's National
Infrastructure Security Co-ordination Centre.
The flaw affecting the Internet's "tranmission
control protocol," or TCP, was discovered late last
year by a computer researcher in Milwaukee, Paul
"Tony" Watson, 36, who said he identified a
method to reliably trick personal computers and routers
into shutting down electronic conversations by resetting
the machines remotely.
Routers continually exchange important updates about
the most efficient traffic routes between large networks.
Continued successful attacks against routers can cause
them to go into a stand-by mode, known as
"dampening," that can persist for hours.
Experts previously maintained such attacks could take
between four years and 142 years to succeed because they
require guessing a rotating number from roughly 4 billion
possible combinations. Mr. Watson said he is able to guess
the proper number in as few as four attempts, which can be
accomplished within seconds.
"The biggest concern is [the effect on routers]
because of the risk of bringing down the Internet or
severely disrupting traffic on the Internet," Mr.
Already in recent weeks, some U.S. government agencies
and companies operating the most important digital
pipelines have quietly fortified their own vulnerable
systems because of early warnings communicated by some
security organizations. The White House has expressed
concerns especially about risks to crucial Internet
routers, since attacks against them could profoundly
disrupt on-line traffic.
"Any flaw to a fundamental protocol would raise
significant concern and require significant attention by
the folks who run the major infrastructures of the
Internet," said Amit Yoran, the U.S. government's
cybersecurity chief. The new flaw has dominated
discussions since last week among experts in close-knit
The public announcement coincides with a presentation
Mr. Watson expects to make Thursday at a popular Internet
security conference in Vancouver, where Mr. Watson said he
will reveal full details of his research.
Mr. Watson, who runs the www.terrorist.net Web site,
predicted that hackers will understand how to begin
launching attacks "within five minutes of walking out
of that meeting."
"It's fairly easy to implement," Mr. Watson
said. "Someone walking out of the conference would
immediately understand. No matter how vague I am, people
will figure it out."