Adobe patches under-attack Reader bug

Ships emergency update to plug a hole hackers have exploited for weeks using rigged PDFs

Adobe today issued an emergency update for its popular Reader PDF software that patched two critical vulnerabilities, including one attackers have exploited for weeks.

The more notable flaw fixed in Reader 9.4.1 for Windows and Mac OS X was a bug that hackers have been leveraging since late October using malicious PDF documents. Those attacks have taken advantage of a flaw in Reader's "authplay" component. Authplay is the interpreter that renders Flash content embedded within PDF files.

Successful attacks have dropped a Trojan horse and other malware on victimized Windows PCs.

Authplay has been targeted by malware makers several times this year, most recently in June. Then, Adobe shipped an emergency patch for Flash Player within a week, and followed with a fix for Reader and Acrobat two weeks later.

Adobe followed the same general timeline this time, patching Flash Player first on Nov. 4, then Reader and Acrobat today.

Adobe has defended its two-stage patching -- which some have questioned because active authplay exploits are typically aimed at Reader, not Flash -- by explaining that the fix was first crafted by its Flash development team. The patched "authoplay.dll" file was then handed off to the Reader group to integrate and test with their product.

The second vulnerability addressed Tuesday had been disclosed on the Full Disclosure security mailing list earlier this month. At the time, Adobe said that the flaw could be used to crash Reader, but not Acrobat, and said it was unsure whether an exploit could compromise a computer running the PDF program.

Adobe repeated that analysis today. "These updates resolve a memory corruption vulnerability that could potentially lead to code execution," the company said in an advisory accompanying the updates.

Although Adobe tries to hew to a quarterly patch schedule for Reader and Acrobat, at times it's scuttled those plans to issue rush fixes for critical bugs. That wasn't the case here: Adobe made it a point to remind users that it will still release its next regularly-scheduled Reader update on Feb. 8, 2011.

Only the Windows and Mac versions of Reader and Acrobat were patched today. An updated Reader for Linux/Unix won't ship until Nov. 30. Adobe also postponed a patch for the older Adobe 8.x, which is vulnerable to the second bug.

"Adobe plans to address Adobe Reader version 8.x in the next release," the advisory read.

Neither bug affected the Android version of Reader that Adobe launched in August.

Reader was last patched Oct. 5 in a 23-fix update one security expert called a "double-whammy."

Adobe Reader and Acrobat for Windows and Mac OS X can be downloaded using the links included in Tuesday's advisory. Alternately, users can call up the programs' built-in update mechanisms to grab the new versions.

Join the CSO newsletter!

Error: Please check your email address.

Tags security

More about Adobe SystemsLinux

Show Comments

Featured Whitepapers

Editor's Recommendations

Solution Centres

Stories by Gregg Keizer

Latest Videos

  • 150x50

    CSO Webinar: The Human Factor - Your people are your biggest security weakness

    ​Speakers: David Lacey, Researcher and former CISO Royal Mail David Turner - Global Risk Management Expert Mark Guntrip - Group Manager, Email Protection, Proofpoint

    Play Video

  • 150x50

    CSO Webinar: Current ransomware defences are failing – but machine learning can drive a more proactive solution

    Speakers • Ty Miller, Director, Threat Intelligence • Mark Gregory, Leader, Network Engineering Research Group, RMIT • Jeff Lanza, Retired FBI Agent (USA) • Andy Solterbeck, VP Asia Pacific, Cylance • David Braue, CSO MC/Moderator What to expect: ​Hear from industry experts on the local and global ransomware threat landscape. Explore a new approach to dealing with ransomware using machine-learning techniques and by thinking about the problem in a fundamentally different way. Apply techniques for gathering insight into ransomware behaviour and find out what elements must go into a truly effective ransomware defence. Get a first-hand look at how ransomware actually works in practice, and how machine-learning techniques can pick up on its activities long before your employees do.

    Play Video

  • 150x50

    CSO Webinar: Get real about metadata to avoid a false sense of security

    Speakers: • Anthony Caruana – CSO MC and moderator • Ian Farquhar, Worldwide Virtual Security Team Lead, Gigamon • John Lindsay, Former CTO, iiNet • Skeeve Stevens, Futurist, Future Sumo • David Vaile - Vice chair of APF, Co-Convenor of the Cyberspace Law And Policy Community, UNSW Law Faculty This webinar covers: - A 101 on metadata - what it is and how to use it - Insight into a typical attack, what happens and what we would find when looking into the metadata - How to collect metadata, use this to detect attacks and get greater insight into how you can use this to protect your organisation - Learn how much raw data and metadata to retain and how long for - Get a reality check on how you're using your metadata and if this is enough to secure your organisation

    Play Video

  • 150x50

    CSO Webinar: How banking trojans work and how you can stop them

    CSO Webinar: How banking trojans work and how you can stop them Featuring: • John Baird, Director of Global Technology Production, Deutsche Bank • Samantha Macleod, GM Cyber Security, ME Bank • Sherrod DeGrippo, Director of Emerging Threats, Proofpoint (USA)

    Play Video

  • 150x50

    IDG Live Webinar:The right collaboration strategy will help your business take flight

    Speakers - Mike Harris, Engineering Services Manager, Jetstar - Christopher Johnson, IT Director APAC, 20th Century Fox - Brent Maxwell, Director of Information Systems, THE ICONIC - IDG MC/Moderator Anthony Caruana

    Play Video

More videos

Blog Posts