[ISN] Activists Find More E-Vote Flaws

[InfoSec News]

http://www.wired.com/news/evote/0,2645,65031,00.html

By Kim Zetter
Sep. 21, 2004

Voting activist Bev Harris and a computer scientist say they found
more vulnerabilities in an electronic voting system made by Diebold
Election Systems, weaknesses that could allow someone to alter votes
in the election this November.

Diebold said Harris' claims are without merit and that if anyone did
manage to change votes, a series of checks and balances that election
officials perform at the end of an election would detect the changes.

Harris demonstrated the vulnerabilities to officials in the California
secretary of state's office several weeks ago and will be showing them
to federal legislative staff and journalists Wednesday in Washington,
D.C. Harris and another activist have filed a lawsuit against Diebold
in California, which the state has joined, maintaining that Diebold
engaged in aggressive marketing to sell millions of dollars worth of
equipment that it knew was insecure. Harris and the activist stand to
make millions from the suit if they and the state win their case.

The vulnerabilities involve the Global Election Management System, or
GEMS, software that runs on a county's server and tallies votes after
they come in from Diebold touch-screen and optical-scan machines in
polling places. The GEMS program generates reports of preliminary and
final election results that the media and states use to call the
winners.

David Jefferson, a computer scientist at Lawrence Livermore National
Laboratory and a member of the California secretary of state's voting
systems panel, agreed with Diebold that election procedures could help
prevent or detect changes in votes, but said that election officials
and poll workers do not always follow procedures. Therefore, election
observers need to know about the vulnerabilities so they can help
reduce the risk that someone could use them to rig an election.

Jefferson added that he doesn't believe that the vulnerabilities show
deliberate malice on Diebold's part to aid fraud, as Harris has
sometimes contended in public statements. But the vulnerabilities do
show incompetence and indicate that Diebold programmers simply don't
know how to design a secure system.

Harris said the problem lies in the fact that GEMS creates two tables
of data that don't always match. One table consists of rows showing
votes for each candidate that were recorded on voting machine memory
cards at each precinct. The other table consists of summaries of that
precinct data. Officials use the raw precinct data to spot-check
accuracy. For example, if all of the machines at a precinct record a
total of 620 votes for Arnold Schwarzenegger, then the data in GEMS
should show 620 votes for Schwarzenegger for that precinct. The
official results that go to the state are based on the vote summaries
produced by GEMS.

When election officials run a report on GEMS on election night, it
creates the vote summaries from the raw precinct data. Then as
absentee and provisional ballots get counted after Election Day and
added into GEMS, the raw data numbers increase, while the vote
summaries remain the same until the next time officials run a summary
report and it regenerates totals from the raw precinct data.

Harris said it's possible to alter the vote summaries while leaving
the raw data alone. In doing so, the election results that go to state
officials would be manipulated, while the canvas spot check performed
on the raw data would show that the GEMS results were accurate.  
Officials would only know that the summary votes didn't match precinct
results if they went back and manually counted results from each
individual polling place and compared them to the vote summaries in
GEMS.

Diebold said because the two sets of data are coupled in GEMS it would
be impossible for someone to change the summaries without changing the
precinct data that feeds the summaries. And if they did, the system
would flag the change.

But Harris said it's possible to change the voting summaries without
using GEMS by writing a script in Visual Basic -- a simple, common
programming language for Windows-based machines -- that tricks the
system into thinking the votes haven't been changed. GEMS runs on the
Windows operating system.

The trick was uncovered by Herbert Thompson, director of security
technology at Security Innovation and a teacher of computer security
at the Florida Institute of Technology. Thompson has authored several
nonfiction books on computer security and co-authored a new novel
about hacking electronic voting systems called The Mezonic Agenda:  
Hacking the Presidency.

After Harris met Thompson at the Defcon hacker conference this year,
she asked him to examine the GEMS program. He found he could write a
five-line script in the Notepad text editor that would change the vote
summaries in GEMS without changing the raw precinct data. The auditing
log in GEMS wouldn't record the change because it only tracks changes
that occur within GEMS, not changes that occur on the computer outside
of GEMS.

After writing the script, Thompson saved it as a Visual Basic file
(.vbs) and double-clicked it to execute it.

The command happens in the background where no one can see it. To
verify that the changes occurred, Thompson could write another script
to display the vote data in a message box after the change. Once the
scripts finished their work, they would go into the Recycle Bin, where
Thompson could delete them.

When Harris demonstrated the vulnerability to officials in California,
she opened the GEMS program to show that the votes changed as the
script commanded them to.

"You have to know in advance what you want to change," Thompson said,
"but it's pretty easy to write a script to find the data that you want
to change. If you want Stan Smith to have more votes than he currently
has, you write a line of your script that says select everything in
the table where candidate equals Stan Smith, and increment the votes.  
Then you delete the votes from another candidate by the same amount."

Thompson acknowledged that the hack would take an insider with
knowledge of the voting system and election procedures and access to
GEMS. But this could include technical people working for a county or
Diebold employees who sometimes assist technically challenged election
officials on election night. It's unlikely that unsavvy election
officials or observers would notice or understand the significance of
someone writing five lines of code in Notepad.

Thompson was pretty stunned to find that some of the same
vulnerabilities that appear in the Diebold system appear in the
fictional voting system he and his co-author created in their recent
novel.

"When we wrote the book, we thought the election system it described
was a bit far-fetched," Thompson said. "We thought it's impossible
that any real voting system would have these problems. Then we saw the
GEMS software, and it had four of the vulnerabilities that we wrote
about in the book."

Thompson said Diebold could easily have designed the system to use
cryptographic hashes to detect if vote summaries changed when they
weren't supposed to change. But he said the company probably never
imagined a scenario in which someone would change the vote data
through Windows, bypassing the audit logs.

There is one way in which changing vote totals in GEMS might not work.  
If someone changed the summary totals before all precinct votes came
in, the altered summary votes would be written over with the new
precinct data once election officials ran another summary report. But
Harris said that "a hidden program for vote manipulation" exists in
GEMS that could allow "any teenager or terrorist with a laptop" or
"anyone with an agenda or a profit motive" to trick the system into
thinking the votes haven't changed by using what Harris calls a
"two-digit code" or trigger in GEMS.

Thompson said the "hidden program" is more of a feature in GEMS that
is put there for a good reason, but is easily abused. GEMS has a
method for flagging whether vote data is old or up-to-date by marking
it with a 0 or a -1. Thompson said it's likely that when election
officials run a new summary report, the 0 and -1 tell the program
which data is old and which is new or updated. But someone could trick
the system into thinking that old data is updated data by switching
the numbers. Harris was able to do this easily in demonstrations.

When asked to comment on this, Diebold sent Wired News an excerpt from
a seven-page rebuttal that it distributed to election officials to
counter Harris' claims. The excerpt said that the flagging feature is
"typically used (for example) to reset any test results that were
uploaded as part of any pre-election testing." No further explanation
of this feature was forthcoming.

But speaking generally on the vulnerabilities Harris mentions, Diebold
spokesman David Bear said by phone that no one would risk manipulating
votes in an election because it's against the law and carries a heavy
penalty. He also said that election "policies and procedures dictate
that no (single) person has access or is in control of a (voting)  
system," so it would be impossible for anyone to change votes on a
machine without others noticing it. And even if someone managed to
change the votes, auditing procedures would detect it.

Diebold spokesman Mark Radke said that after an election, counties are
supposed to go back to the memory cards taken from voting machines and
manually add vote totals stored on the cards as well as vote totals on
a paper printout that poll workers take from each machine at the close
of the polls. Officials compare these totals to the GEMS summary
totals and if there is a discrepancy, Radke said, the totals from the
memory cards take precedence over the GEMS totals.

Jefferson, the Lawrence Livermore computer scientist, agreed that
election procedures usually indicate that there should not be one
person operating the counting software. He also agreed with Bear that
officials could catch discrepancies in vote totals if they went back
and manually added up the results from every individual polling place
and compared the totals with the tallies in the summary report. But
Jefferson said that election officials and poll workers don't always
follow procedures. In the California March primary, he pointed out,
several counties refused to follow procedures that were requested by
the secretary of state's office and others failed to follow procedures
that are mandated under California election law.

Rather than creating a system that relies on the "perfect execution of
(poll worker) procedures," Jefferson said, Diebold should have
designed the system to better prevent fraud.

"You don't want to make up for poor design by adding more burden to
beleaguered poll workers and election officials who don't understand
the reasons for all of the rules that they have to obey and (are
therefore) likely to cut corners," Jefferson said.

As for why Diebold would have designed such a poor system, Jefferson
thinks the company simply didn't know how to do it any better.

"There are a lot of reasons why you might want parallel tables of vote
totals," Jefferson said. "But there are better designs that avoid
(these vulnerabilities) entirely. If you are not a world-class
designer, if you're making it up as you go along and not deeply
educated in data management, this is the kind of design you might come
up with.

"I think the designers of the Diebold system never seriously
understood what it would take to prevent vote manipulation by
insiders," Jefferson said. "I consider that to be inexcusable."