Author Archives: JimC_Security

Blog Re-design

Hello everyone,

As I am sure you have noticed, this blog has just undergone a re-design. It’s intention is to ease navigation and provide access to previous posts which you may find helpful.

I hope you like the new image at top of the page in addition to adverts no longer being present at the end of every page. Please let me know if you don’t like this new design and I will endeavor to improve it for you.

Thank you.

Pwn2Own 2017 Results

The final day of competition within Pwn2Own 2017 took place on Friday, 17th March. Full details of how the individual teams performed and how many exploits were successful are available here , here and here.

In summary the following products were successfully exploited:

Adobe Flash
Adobe Reader
Apple Safari
Apple macOS (mostly the macOS kernel)(defined)
Microsoft Edge
Microsoft Windows kernel
Mozilla Firefox
Ubuntu Linux
VMware Workstation

The contest saw 51 vulnerabilities used and a total of USD$833,000 awarded to the contestants (a very large increase over last year’s USD$460K). As I noted last year, many vulnerabilities once again were present within the macOS and Windows kernels specifically:

Apple macOS kernel:
race condition (defined)
information disclosures (defined)
out of bounds (OOB) bug (defined)

Microsoft Windows kernel:
integer overflows (defined)
buffer overflows (defined)
uninitialised buffers (discussed here)
use-after-free (defined here and here)
information disclosures
out of bounds (OOB) bug
race condition

As before Microsoft and Apple need to do more thorough static analysis/auditing/fuzzing (defined here and here) of the kernel to find and resolve vulnerabilities before they are exploited. It is a surprise this year again highlights this short coming which secure coding practices e.g. Microsoft’s SDL and Adobe’s SPLC (among others) were intended to reduce.

Of note is; Mozilla Firefox released Firefox 52.0.1 to resolve an integer flow vulnerability in less than 1 day after it’s disclosure during Pwn2Own; a fantastic response time.

We can again look forward to these vulnerabilities being addressed over the coming months; helping to make our products more secure.

Thank you.

Proton Trojan targeting Apple macOS discovered

Earlier this month Sixgill, a cyber intelligence company has provided information on a recently discovered trojan for Apple macOS systems. It is being sold on the underground Russian cybercrime forums and acts as a remote administration tool (RAT)(defined). It sells under the name of Proton for 100 Bitcoin (more than USD$100,000) but now allows unlimited installations for 40 Bitcoin or a single installation for 2 Bitcoin.

Since the trojan is a RAT (discussed above) it allows an attacker to have full control of a victim’s system which includes controlling file uploads and downloads, monitoring keyboard presses, taking screenshots and webcam surveillance.

Sixgill theorizes the trojans developers bypassed/worked around Apple’s Developer ID program allowing this “application” to appear harmless while possibly exploiting an unknown zero day vulnerability (defined) within macOS to root privileges (defined) over the victim system.

How can I protect myself from this malware?
Since the trojan allows full control of an over an infected system, this will complicate removal since the attackers could easily attempt to resist or undo removal actions. Malwarebytes state this trojan is not in widespread use and they have been unable so far to obtain a sample of it. Moreover, VirusTotal did not have a sample to provide to them.

Apple added detections for this trojan to their XProtect (defined) anti-malware security feature; however as detailed in this TechRepublic article the trojans creators can easily modify it to avoid Apple’s signatures.

Further information on this trojan is available in this Softpedia article. TechRepublic provides a detailed list of recommendations within their article to prevent infection by this threat.

Thank you.

March 2017 Security Updates Summary

As you know Microsoft and Adobe released their scheduled monthly security updates. For Microsoft this release was anticipated especially since last month’s set was delayed.

Within the above linked to post I predicted Microsoft would make a large number of updates and they did just that. 17 bulletins in total are now available. These updates address 138 vulnerabilities listed within Microsoft’s new Security Update Guide. These vulnerabilities are more formally known as CVEs (defined).

Once again; there are no Known Issues listed within their March summary page. At the time of writing the IT Pro Patch Tuesday blog does not list any Known Issues. However, please check it before deploying your security updates just to be sure. As always, if any issues do arise, those pages should be your first places to check for solutions.
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Adobe issued two security bulletins today. One affecting Adobe Flash and the other for Adobe Shockwave Player. The Flash Player bulletin resolves 7x priority 1 vulnerabilities. While the Shockwave bulletin resolves 1x priority 2 vulnerability. These priority rating are explained in the previous link.
Depending on which version of Flash Player you have, please review the Adobe security bulletin or Microsoft bulletin as appropriate and apply the recommended updates. Google Chrome users will have the updated installed automatically alongside the updated version of Google Chrome which made available last week.

If you use Flash or Adobe Shockwave, please review the security bulletins linked to above and apply the necessary updates. The Flash update should be installed as soon as possible since exploit kits (defined) tend to take advantage of newly disclosed vulnerabilities very quickly.

You can monitor the availability of security updates for most your software from the following websites (among others) or use Secunia PSI:

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US Computer Emergency Readiness Team (CERT) (please see the “Information on Security Updates” heading of the “Protecting Your PC” page):

https://www.us-cert.gov/

A further useful source of update related information is the Calendar of Updates. News/announcements of updates in the categories of General Software, Security Software and Utilities are available on their website. The news/announcements are very timely and (almost always) contain useful direct download links as well as the changes/improvements made by those updates (where possible).

If you like and use it, please also consider supporting that entirely volunteer run website by donating.
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If you use any of the above software, please install the appropriate updates as soon as possible. Steps for installing updates for Windows are provided on the “Protecting Your PC” page.

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Update: 22nd March 2017:
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I wish to provide information on other notable updates from this month which I would recommend you install if you use these software products:

Notepad++ version 7.3.3

VideoLAN VLC Media version 2.2.5 (release currently in progress)

Malwarebytes Anti-malware version 3.0.6 CU3 (with Component package version: 1.0.75):
It is unknown how many vulnerabilities this addresses but this forum post mentions their resolution.

More details of the vulnerabilities resolved by Malwarebytes 3.0.6 CU3 have emerged. Researchers responsibly disclosed a technique which uses Microsoft’s Application Verifier to hijack an anti-malware application. More details of this vulnerability are available here and here.

Mozilla Firefox 52.0.1 (more details in this post on Pwn2Own 2017)

VMware Workstation 12.5.4 (relevant security advisories are here and here)

Wireshark 2.2.5 and 2.0.11

Putty 0.68 (while released in February; it contains important security changes)

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For the 17 Microsoft bulletins this month, I will prioritize the order of updates for you below:

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Critical severity:
Windows Graphics Component

Windows SMB Server

Microsoft Edge

Internet Explorer

Windows Hyper-V

Windows PDF

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Important Severity
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The update for Microsoft Office should be installed next due to it’s criticality. With the follow updates after it:

Microsoft Exchange

Microsoft IIS

Active Directory Federation Server

As always you can find detailed information on the contents of each security bulletin is published each month within ComputerWorld’s Patch Tuesday Debugged column.

Another security pre-caution that you may wish to take if you have Microsoft EMET (please ensure your version of EMET is the most recent version 5.52) installed is to use it to protect you from Adobe Flash being used to exploit vulnerabilities when you open a Microsoft Office document or Adobe PDF file. I provide recommendations of how to do this at the end of the July 2015 Update Summary.
Please note that Microsoft EMET will be out of support on the 31st of July 2018.

As is my standard practice, I would recommend backing up the data on any device for which you are installing updates to prevent data loss in the rare event that any update causes unexpected issues.

Thank you.

Malware uses DNS protocol for command and control

In early March two Cisco Talos security researchers Edmund Brumaghin and Colin Grady released details of a multi-stage trojan horse which communicates with it’s creator(s) using the Domain Name Service (DNS)(defined) protocol.

Since DNS is a widely used essential protocol it is often allowed to pass through corporate and personal firewalls. The source of the malware is an email containing an attachment reportedly secured with McAfee. The attachment is a Microsoft Word document which when opened requests to enable macros (defined). If the user enables macros the macros unpacks a Microsoft PowerShell script (a computer programming language usually used for automating system administration tasks) which forms the second stage of the attack.

Next the script checks if currently logged in user has administrator rights for their Windows account and checks the installed version of PowerShell. The script then adds a backdoor (defined). If the earlier check for administrative privileges was positive the backdoor will persist after restarting or powering off the system. This backdoor uses DNS to receive and carry out commands from it’s creators.

While analysing this threat, the above mentioned security researchers did not witness the malware receiving DNS commands due to its targeted nature.

How can I protect myself from this threat?
Sine this malware arrives via email, please verify the emails you receive are genuine and not attempting to deliver malware. SANS recently provided extra advice on this (March 6th : source)

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Don’t Trust Links Sent in Email Messages March 6, 2017
A common method cyber criminals use to hack into people’s computers is to send them emails with malicious links. People are tricked into opening these links because they appear to come from someone or something they know and trust. If you click on a link, you may be taken to a site that attempts to harvest your information or tries to hack into your computer. Only click on links that you were expecting. Not sure about an email? Call the person to confirm they sent it.
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In addition if you inspect network traffic within your corporate network, please consider adding DNS to the list of protocols analysed. Attackers are likely to leverage this widely allowed protocol for command and control (defined) going forward.

Thank you.

WD My Cloud NAS Vulnerabilities

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Update: 22nd March 2017:
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Western Digital have made available firmware updates to My Cloud Mirror, EX2 and EX4 models. The updates are available from http://support.wdc.com/downloads.aspx

They resolve some of the critical vulnerabilities identified in these products. Steps to update the firmware are available in this Softpedia article.

Thank you.

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Original Post:
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Earlier this month a freelance security researcher known as Zenofex publically disclosed (defined) a total of 85 security vulnerabilities within the Western Digital (WD) MyCloud Network Attached Storage (NAS)(defined) devices

The vulnerabilities consist of authentication bypasses and code execution (carrying out instructions/steps of an attacker’s choice) and the upload/download of the data the device contains. Since the researcher did not receive cooperation with addressing previously communicated vulnerabilities from WD in the past they chose not to responsibly disclose (defined) these vulnerabilities.

After this disclosure, SEC Consult Vulnerability Lab (SCVL) provided further details of these vulnerabilities to the wider security community. For some of the 85 issues disclosed they had contacted WD in January 2017 and disclosed some of the details on the 20th of February. These vulnerabilities range from : command injection vulnerabilities, a stack-based buffer overflow (defined) bug and a cross-site request forgery flaw (defined)

In December 2016 WD issued fixes for some of the vulnerabilities discovered but created further vulnerabilities which resulted in the very same outcome they were trying to address.

How can I protect myself from these vulnerabilities?
Unfortunately, due to the very large number of vulnerabilities disclosed it will take a significant duration of time to resolve them all (especially if inadvertently; further vulnerabilities become evident; as has happened before).

If you use this NAS device; the data it contains will be at elevated risk of compromise while WD works to resolve these vulnerabilities. I would recommend ensuring these devices are not accessible to the external internet. Shodan may be of assistance to you in determining this. More information on Shodan is available in a previous blog post.

Please create backups of the data these NAS devices contain and store them on other devices until these vulnerabilities are resolved. Monitor WD’s website and install new firmware releases as they become available.

While Western Digital issued fixes for some of the vulnerabilities in December 2016, the independent security researcher found the fixes created another vulnerability with the same results they intended to resolve.

In addition, within this ThreatPost article WD recommends:

“My Cloud users contact our Customer Service team if they have further questions; find firmware updates; and ensure their My Cloud devices are set to enable automatic firmware updates.”

I will update this post as new information on the relevant updates becomes available.

Thank you.

Cloudflare addresses data leak

For 5 days within February this year; an information disclosure issue affected Cloudflare’s infrastructure. This led to their systems inadvertently leaking private session keys, website cookies, encryption keys and passwords.

Why should this vulnerability be considered important?

The scale of the issue was large, affecting an estimated 2 million websites. This flaw was due to a coding error within a parser (defined) (undetected at the time) used to modify HTML webpages and related to how the memory containing buffers (defined) of their NGINX (defined) web server functioned. Google Project Zero vulnerability researcher Tavis Ormandy contacted Cloudflare over Twitter who mitigated the issue in 47 minutes and completed their work in less than 7 hours; an incredibly swift resolution. Cloudflare later noted it would usually take 3 months to resolve an issue similar to this.

How can I protect myself from this vulnerability?

Cloudflare documented their findings of this incident within this blog post. Their analysis shows no evidence of attackers using the leaked information for malicious account access, accessing sensitive information or fraudulent purchases (in the case of exposed credit card numbers).

Cloudflare is continuing to review the leaked information and working to remove it from third party caches. They have committed to a review (both internal and with the assistance of external auditor Veracode) of the parser code which inadvertently lead to this information leakage.

As a precaution I would recommend monitoring any affected accounts for unwanted activity and change passwords and enable 2 factor authentication should any unwanted activity take place. The list of affected websites is here.

Further discussion of the impact of this issue is available from this SANS forum post and this Softpedia news article.

Thank you.