Adobe Patches Incomplete Fix for NTLM Credential Leaking Bug (CVE-2018-15979)

save
Share and earn Cybytes
Facebook Twitter Google+ LinkedIn Email

Researchers have reported an incomplete fix for CVE-2018-4993, an NTLM credential leaking vulnerability that was supposed to be patched in May 2018. Adobe has now released a complete fix.

Background

On November 13, Adobe published its monthly security bulletins as part of its monthly release cycle in conjunction with Microsoft’s Patch Tuesday. The November security bulletins include a fix for a vulnerability that was believed to have been patched in May 2018’s security bulletins. However, security researchers at EdgeSpot discovered that the May 2018 fix was incomplete.

Vulnerability details

Researchers at Check Point Software Technologies originally reported this vulnerability to Adobe earlier in 2018. The vulnerability, CVE-2018-4993, is an information disclosure bug that leaks NT LAN Manager (NTLM) credentials through a feature of Portable Document Files (PDFs) that allows embedding remote documents and files. These credentials can be leaked when an attacker sends a specially crafted PDF file to a victim and includes the NTLM hash and challenge along with user and domain details.

Source: Checkpoint

Adobe reportedly patched this vulnerability in May 2018 as part of its security bulletin, APSB18-09. However, researchers at EdgeSpot, makers of an exploit detection service, determined that the May 2018 patch for CVE-2018-4993 was incomplete. The researchers examined two malicious PDF files (here and here) submitted to VirusTotal in May 2018 and determined the vulnerability still works using the latest version of Adobe Reader.

It appears that when Adobe issued their patch for this vulnerability in May 2018, it only patched one of two action types required when embedding remote documents and files. The two action types are:

  • GoToR (GoToRemote)
  • GoToE (GoToEmbedded)

EdgeSpot researchers say Adobe only patched GoToR and not GoToE based on the malicious PDF files they examined, both of which contained the GoToE action type. After reporting this to Adobe in early November, it was identified as a new CVE, CVE-2018-15979 and patched in Adobe’s November security bulletins.

Urgently required actions

Customers and users are strongly advised to upgrade to the latest versions of Adobe Acrobat and Acrobat Reader, which can be found here.

Identifying affected systems

A list of Nessus plugins to identify this vulnerability can be found here.

Get more information

Learn more about Tenable, the first Cyber Exposure platform for holistic management of your modern attack surface. Get a free 60-day trial of Tenable.io Vulnerability Management.

Share this post and earn Cybytes
Facebook Twitter Google+ LinkedIn Email
Follow
1594 Followers
About Tenable
Tenable™, Inc. is the Cyber Exposure company. Over 24,000 organizations of all sizes around the globe rely on Tenable to manage and measure their modern attack surface to accurately understand and reduce cyber risk. As the creator of Nessus®, Tenable built its platform from the ground up to deeply understand assets, networks and vulnerabilities, extending this knowledge and expertise into Tenable.io™ to deliver the world’s first platform to provide live visibility into any asset on any computing platform. Tenable customers include over 50 percent of the Fortune 500, large government agencies and organizations across the private and public sectors. Learn more at tenable.com.
Promoted Content
Five Steps to Building a Successful Vulnerability Management Program
Is your vulnerability management program struggling? Despite proven technology solutions and the best efforts of IT teams, unresolved vulnerabilities remain an ongoing source of friction and frustration in many organizations. Regardless of how many vulnerabilities are fixed, there will always be vulnerabilities that can’t easily be remediated – and too often, finger-pointing between IT teams and business groups can ensue.

Our Revolution

We believe Cyber Security training should be free, for everyone, FOREVER. Everyone, everywhere, deserves the OPPORTUNITY to learn, begin and grow a career in this fascinating field. Therefore, Cybrary is a free community where people, companies and training come together to give everyone the ability to collaborate in an open source way that is revolutionizing the cyber security educational experience.

Cybrary On The Go

Get the Cybrary app for Android for online and offline viewing of our lessons.

Get it on Google Play
 

Support Cybrary

Donate Here to Get This Month's Donor Badge

 
Skip to toolbar

We recommend always using caution when following any link

Are you sure you want to continue?

Continue
Cancel