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New Word, Windows Vulnerabilities Surface
It's been a rocky 2007 for Microsoft Corp.'s Word productivity app, but April
might just be the cruelest month of all. Redmond this week was alerted to a
spate of new security flaws in its vulnerability-ridden Word -- only this time,
the victim is Microsoft's brand-new Word 2007 application.
Elsewhere, security mailing lists were abuzz with talk of another new Windows
vulnerability: a flaw in Microsoft's Windows Help implementation.
The new Word flaws affect only the Office 2007-flavored version of that product.
That wasn't the case in February, when Microsoft released a roll-up
fix to patch a quartet of vulnerabilities in its Word 2000, Word 2002 (XP),
Word 2003 and Word for Macintosh. Several of the vulnerabilities were linked
to known zero day attacks. Ironically, Word 2007 was invulnerable to those attacks.
The new flaws, which were disclosed on the Bugtraq mailing list, could make
Word 2007 susceptible to Remote Code Execution and denial-of-service (DoS) exploits,
according to their discoverer, Israeli security researcher Mati Aharoni. The
more serious of the two -- a buffer
overflow in Word 2007's WWLIB.DLL -- can allow both DoS and remote code
execution attacks, Aharoni claimed.
He also disclosed the possibility of "multiple
unspecified vulnerabilities" in Word 2007 that attackers could exploit
to cause DoS. Aharoni has developed proof-of-concept code in the form of malicious
documents.
Neither issue has yet been confirmed by Microsoft; their status at the Common
Vulnerabilities and Exposures (CVE) repository is currently listed as "Under
Review."
Little is known about the impact of the Windows
Help flaw, which affects files with the .HLP extension. An attacker can
exploit it by crafting a malicious .HLP file which -- when executed -- triggers
a heap-based buffer overflow. The complete ramifications of doing so are, at
present, unknown. A similar
issue was identified last year; that vulnerability was linked to a remote
code execution exploit.
The most recent Windows Help vulnerability, like the Word 2007 flaws, was identified
by Aharoni.
About the Author
Stephen Swoyer is a Nashville, TN-based freelance journalist who writes about technology.