Feeds

Unofficial fix brings temporary relief for critical Adobe vuln

User beware

Choosing a cloud hosting partner with confidence

Security researchers have released what they say is an unofficial fix for the critical Adobe Reader vulnerability that's being actively exploited to install malware on machines running Microsoft Windows.

The download replaces a buggy strcat call in a font-rendering DLL module with a more secure function, according to this explanation from the researchers at penetration-testing firm RamzAfzar. Protecting yourself from the underlying stack overflow flaw is as easy as overwriting the existing CoolType.dll located in the Acrobat Reader folder with the revised one.

“We've decided to modify this strcat call and convert it to strncat,” they wrote. “Why? Because strncat at least receives the buffer size and how much bytes you want to copy from src to dest.”

H D Moore, the CSO of Rapid7 and chief architect of the Metasploit project, said he hasn't had a chance to test whether the update truly patches the gaping hole left by Adobe developers. But he said the approach seemed to make sense.

“If anything, it's a great proof point on the overhead of the software industry,” he said.

Adobe has said it won't release an update for Reader until October 4. That means users of the near-ubiquitous program have another three weeks until they are protected against a sophisticated threat that criminals are already exploiting with aplomb. The delay wasn't lost on the people from RamzAfzar, who said their fix was easy even from their considerably less advantaged position.

“We patched it without having source code in two hours and they need 20 days with code, looks odd to me!”

It's only fair to point out that unlike RamzAfzar, Adobe has to complete a rigorous battery of tests to make sure the changes don't brick millions of machines running Windows, OS X, and Unix. It's also worth pointing out that the vast majority of Reader users could protect themselves by using an alternative PDF viewer that isn't as widely targeted.

Over the past few years, unofficial patches have become fairly common, with the most recent memorable one released in February for another critical Reader bug. Whether they make sense or not, they're probably here to stay. ®

Choosing a cloud hosting partner with confidence

More from The Register

next story
You really need to do some tech support for Aunty Agnes
Free anti-virus software, expires, stops updating and p0wns the world
Privacy bods offer GOV SPY VICTIMS a FREE SPYWARE SNIFFER
Looks for gov malware that evades most antivirus
Patch NOW! Microsoft slings emergency bug fix at Windows admins
Vulnerability promotes lusers to domain overlords ... oops
HACKERS can DELETE SURVEILLANCE DVRS remotely – report
Hikvision devices wide open to hacking, claim securobods
Astro-boffins start opening universe simulation data
Got a supercomputer? Want to simulate a universe? Here you go
State Dept shuts off unclassified email after hack. Classified mail? That's CLASSIFIED
Classified systems 'not affected' - but, is this reconnaissance?
prev story

Whitepapers

Why cloud backup?
Combining the latest advancements in disk-based backup with secure, integrated, cloud technologies offer organizations fast and assured recovery of their critical enterprise data.
Forging a new future with identity relationship management
Learn about ForgeRock's next generation IRM platform and how it is designed to empower CEOS's and enterprises to engage with consumers.
How to determine if cloud backup is right for your servers
Two key factors, technical feasibility and TCO economics, that backup and IT operations managers should consider when assessing cloud backup.
High Performance for All
While HPC is not new, it has traditionally been seen as a specialist area – is it now geared up to meet more mainstream requirements?
Security and trust: The backbone of doing business over the internet
Explores the current state of website security and the contributions Symantec is making to help organizations protect critical data and build trust with customers.