Vmyths.com Virus Hysteria Alert
Truth About Computer Security Hysteria
{15 September 2004, 01:55 CT}
CATEGORIES: (1) Misconceptions about a real computer security threat
(2) A historical perspective on recent hysteria
Microsoft has issued a "critical" alert regarding a "buffer overrun" in
software it uses to display JPEG images. In theory, if you try to view a
specially crafted JPEG file, it could take over your computer and do whatever
it wishes. Microsoft has released a security patch to fix this buffer overrun.
Vmyths urges you to download the patch, install it, and get on with your life.
Buffer Overrun in JPEG Processing Could Allow Code Execution:
http://www.microsoft.com/technet/security/bulletin/MS04-028.mspx
Vmyths believes media outlets will POUNCE on this story, because (a) Microsoft
announced a "critical" vulnerability in the way its software reads an
ubiquitous file type, and (b) computer emergency response teams have issued
their own alerts. Watch for breathless speculation and hysteria in the coming
days. Some naïve system administrators may tell reporters they'll delete JPEG
files from emails and refuse to let web browsers display JPEG files, "strictly
as a precaution." (We don't expect anyone will implement this Draconian
measure for very long. We believe too many users will clamor against it.)
Remember this when virus hysteria strikes:
http://Vmyths.com/resource.cfm?id=31&page=1
Microsoft's "JPEG Processor" vulnerability manifests itself as a buffer overrun
in a piece of software. It is NOT caused by the JPEG file format itself.
Buffer overruns are extremely common: you'll find them in almost every large
software application (even antivirus software). They can create situations
where even a filename itself can wreak havoc. By definition, every buffer
overrun will eventually join its brothers in the land of obscurity.
Buffer overruns in antivirus software:
http://zdnet.com.com/2100-11-515441.html
The "Code Red" worms successfully exploited a buffer overrun in 2001, and
Vmyths believes some reporters will allude to this -- as if to imply a horrific
JPEG attack may be just around the corner. Buffer overruns are extremely
common, yet they only rarely ever get exploited. Researcher Georgi Guninski,
for example, publishes "proof of concept" exploits for many of the "critical"
buffer overruns he finds. Guninski's exploits have never made a splash despite
his best efforts.
A little history -- this isn't the first time an image file format has come
under fire. An April Fool's joke targeted JPEG files a decade ago:
1994 April Fool "JPEG virus" alert:
http://www.2meta.com/april-fools/1994/JPEG-Virus.html
In 2001, researchers claimed a specially crafted GIF file could be used to
cause a buffer overrun in Microsoft Outlook. It was purely a coincidence that
a GIF file could exploit this threat.
In 2002, the "Perrun" virus added software to the computers it infected, then
it modified the Windows registry so future viruses could "ride" inside a JPEG
file. The virus writer could have chosen to do the same thing with GIF files
or even TEXT files. Antivirus vendor Sophos urged restraint over the Perrun
virus, saying "some anti-virus vendors may be tempted to predict the end of the
world as we know it, or warn of an impending era when all graphic files should
be treated with suspicion. Such experts should be ashamed of themselves."
McAfee gets slapped in 2002 for "JPEG virus" alert:
http://www.sophos.com/virusinfo/articles/perrun.html
Vmyths suspects a hoax virus alert will arise with instructions to delete the
JPEG registered file type in Windows. (It's practically a self-fulfilling
prophesy.) Such a hoax will play on the user's misconception of the threat.
Don't take unsolicited advice from people who are NOT experts. Users will
self-damage their operating systems if they delete the JPEG registered file
type.
False Authority Syndrome
http://Vmyths.com/fas/fas1.cfm
Stay calm. Stay reasoned. And stay tuned to Vmyths.
Rob Rosenberger, editor
http://Vmyths.com
Rob@Vmyths.com
(319) 646-2800
Acknowledgements:
Phone call from Kevin Poulsen, SecurityFocus
CATEGORIES: (1) Misconceptions about a real computer security threat
(2) A historical perspective on recent hysteria
--------------- Useful links ------------------
Common clichés in the antivirus world
http://Vmyths.com/resource.cfm?id=22&page=1
-----
NTBugtraq Editor's Note:
Want to reply to the person who sent this message? This list is configured such
that just hitting reply is going to result in the message coming to the list,
not to the individual who sent the message. This was done to help reduce the
number of Out of Office messages posters received. So if you want to send a
reply just to the poster, you'll have to copy their email address out of the
message and place it in your TO: field.
-----
