Category: Cyber Security

CVE-2019-19781 – Vulnerability in Citrix Application Delivery Controller

Feb 11, 2020 by Sam Taylor

Description of Problem

A vulnerability has been identified in Citrix Application Delivery Controller (ADC) formerly known as NetScaler ADC and Citrix Gateway formerly known as NetScaler Gateway that, if exploited, could allow an unauthenticated attacker to perform arbitrary code execution.

The scope of this vulnerability includes Citrix ADC and Citrix Gateway Virtual Appliances (VPX) hosted on any of Citrix Hypervisor (formerly XenServer), ESX, Hyper-V, KVM, Azure, AWS, GCP or on a Citrix ADC Service Delivery Appliance (SDX).

Further investigation by Citrix has shown that this issue also affects certain deployments of Citrix SD-WAN, specifically Citrix SD-WAN WANOP edition. Citrix SD-WAN WANOP edition packages Citrix ADC as a load balancer thus resulting in the affected status.

The vulnerability has been assigned the following CVE number:

• CVE-2019-19781 : Vulnerability in Citrix Application Delivery Controller, Citrix Gateway and Citrix SD-WAN WANOP appliance leading to arbitrary code execution

The vulnerability affects the following supported product versions on all supported platforms:

• Citrix ADC and Citrix Gateway version 13.0 all supported builds before

• NetScaler ADC and NetScaler Gateway version 12.1 all supported builds before

• NetScaler ADC and NetScaler Gateway version 12.0 all supported builds before

• NetScaler ADC and NetScaler Gateway version 11.1 all supported builds before

• NetScaler ADC and NetScaler Gateway version 10.5 all supported builds before

• Citrix SD-WAN WANOP appliance models 4000-WO, 4100-WO, 5000-WO, and 5100-WO all supported software release builds before 10.2.6b and 11.0.3b

What Customers Should Do

Exploits of this issue on unmitigated appliances have been observed in the wild. Citrix strongly urges affected customers to immediately upgrade to a fixed build OR apply the provided mitigation which applies equally to Citrix ADC, Citrix Gateway and Citrix SD-WAN WANOP deployments. Customers who have chosen to immediately apply the mitigation should then upgrade all of their vulnerable appliances to a fixed build of the appliance at their earliest schedule. Subscribe to bulletin alerts at to be notified when the new fixes are available.

The following knowledge base article contains the steps to deploy a responder policy to mitigate the issue in the interim until the system has been updated to a fixed build: CTX267679 – Mitigation steps for CVE-2019-19781

Upon application of the mitigation steps, customers may then verify correctness using the tool published here: CTX269180 – CVE-2019-19781 – Verification Tool

In Citrix ADC and Citrix Gateway Release “12.1 build 50.28”, an issue exists that affects responder and rewrite policies causing them not to process the packets that matched policy rules. This issue was resolved in “12.1 build 50.28/31” after which the mitigation steps, if applied, will be effective.  However, Citrix recommends that customers using these builds now update to “12.1 build 55.18”, or later, where CVE-2019-19781 issue is already addressed.

Customers on “12.1 build 50.28” who wish to defer updating to “12.1 build 55.18” or later should choose one from the following two options for the mitigation steps to function as intended:

1. Update to the refreshed “12.1 build 50.28/50.31” or later and apply the mitigation steps, OR

2. Apply the mitigation steps towards protecting the management interface as published in CTX267679. This will mitigate attacks, not just on the management interface but on ALL interfaces including Gateway and AAA virtual IPs

Fixed builds have been released across all supported versions of Citrix ADC and Citrix Gateway. Fixed builds have also been released for Citrix SD-WAN WANOP for the applicable appliance models. Citrix strongly recommends that customers install these updates at their earliest schedule. The fixed builds can be downloaded from and and

Customers who have upgraded to fixed builds do not need to retain the mitigation described in CTX267679.


Fix Timelines

Citrix has released fixes in the form of refresh builds across all supported versions of Citrix ADC, Citrix Gateway, and applicable appliance models of Citrix SD-WAN WANOP. Please refer to the table below for the release dates.



Citrix thanks Mikhail Klyuchnikov of Positive Technologies, and Gianlorenzo Cipparrone and Miguel Gonzalez of Paddy Power Betfair plc for working with us to protect Citrix customers.

What Citrix Is Doing

Citrix is notifying customers and channel partners about this potential security issue. This article is also available from the Citrix Knowledge Center at

Obtaining Support on This Issue

If you require technical assistance with this issue, please contact Citrix Technical Support. Contact details for Citrix Technical Support are available at

Reporting Security Vulnerabilities

Citrix welcomes input regarding the security of its products and considers any and all potential vulnerabilities seriously. For guidance on how to report security-related issues to Citrix, please see the following document: CTX081743 – Reporting Security Issues to Citrix



Jul 11, 2019 by Sam Taylor

Cohesity vs. Rival Solution:

Comparison from a Business Continuity Perspective

The Business Continuity field is saturated with different solutions, all promising to the do the same thing- keep your business running smoothly and safely post-disaster. But how do you weed through the options to determine which solution is best, and what criteria should you use to do this?

The idea for this blog post came about during a recent visit to a newly acquired client, who was using one of the many solutions for Business Continuity. After asking about the service, our client realized that they had bought it based on affordability, but did not actually analyze the service – and whether it’s good enough for their business. Below, we’ll explore the differences between the above-mentioned solution and Cohesity’s MSP solution (which we currently use at CrossRealms) from technical, process, and financial perspectives. We hope this information can help you think more critically about what’s involved in achieving optimal Business Continuity/Disaster Recovery.

Technical & Process

Let’s start with the functional differences between the rival and the Cohesity MSP solution. The following chart breaks it down:


The Cohesity pricing is around $250/TB per month, depending on the size of the backup and requirements, with a one-year minimum commitment. This includes unlimited machine licensing, cloud backup, and SSD local storage for extremely fast recovery. It also includes Tabletop exercises and other business functions necessary for a complete Business Continuity solution.

The rival solution pricing (depending on the reseller) is around $240/TB per month – including the local storage with limited SSD. This also includes unlimited machine licensing and file recovery. It does not include Tabletop exercises, local SSD, or remote connectivity to their data center by the users in case of catastrophic office failure.


Overall, Cohesity outshines competitors with regards to the initial backup/seeding and Test/Dev processes. While it is slightly more expensive, the extra cost is absolutely worth the added benefits.

We hope this post will start a conversation around what should be included or excluded from a Business Continuity plan, and what variables need to be considered when comparing different products. Please comment with any questions or insight – we’d love to hear your thoughts.


Jul 11, 2019 by Sam Taylor

Case Study #1: Rural Hospitals and New Technologies: Leading the Way in Business Continuity

The purpose of this series is to shed light onto the evolving nature of Business Continuity, across all industries. If you have an outdated plan, the likelihood of success in a real scenario is most certainly diminished. Many of our clients already have a plan in place, but as we start testing, we have to make changes or redesign the solution altogether. Sometimes the Business Continuity plan is perfect, but does not include changes that were made recently – such as new applications, new business lines/offices, etc.

In each scenario, the customer’s name will not be shared. However, their business and technical challenges as they relate to Business Continuity will be discussed in detail.


This case study concerns a rural hospital in the Midwest United States. Rural hospitals face many challenges, mainly in the fact that they serve poorer communities with fewer reimbursements and a lower occupancy rate than their metropolitan competition. Despite this, the hospital was able to surmount these difficulties and achieve an infrastructure that is just as modern and on the leading edge as most major hospital systems.


Our client needed to test their existing Disaster Recovery plan and develop a more comprehensive Business Continuity plan to ensure compliance and seamless healthcare delivery in case of an emergency. This particular client has one main hospital and a network of nine clinics and doctor’s offices.

The primary items of concern were:

  • Connectivity: How are the hospital and clinics interconnected, and what risks can lead to a short or long-term disruption?
  • Medical Services: Which of their current systems are crucial for them to continue to function, whether they are part of their current disaster recovery plan, and whether or not they have been tested.
  • Telecommunication Services: Phone system and patient scheduling.
  • Compliance: If the Disaster Recovery system becomes active, especially for an extended period of time, the Cyber Security risk will increase as more healthcare practitioners use the backup system, and, by default, expose it to items in the wild that might currently exist, but have never impacted the existing live system.

After a few days of audit, discussions, and discovery, the following were the results:

Connectivity: The entire hospital and all clinics were on a single Fiber Network which was the only one available in the area. Although there were other providers for Internet access, local fiber was only available from one provider.

Disaster Recovery Site: Their current Business Continuity solution had one of the clinics as a disaster recovery site. This would be disastrous in the event of a fiber network failure, as all locations would go down simultaneously.

Partner Tunnels: Many of their clinical functions required access to their partner networks, which is done through VPN tunnels. This was not provisioned in their current solution.

Medical Services: The primary EMR system was of great concern because their provider would say: “Yes, we are replicating the data and it’s 100% safe, but we cannot test it with you – because, if we do, we have to take the primary system down for a while.” Usually when we hear this, we start thinking “shitshows”. So, we dragged management into it and forced the vendor to run a test. The outcome was a failure. Yes, the data was replicated, and the system could be restored, but it could not be accessed by anyone. The primary reason was the fact that their system replicates and publishes successfully only if the redundant system is on the same network as the primary (an insane – and, sadly – common scenario). A solution to this problem would be to create an “Extended LAN” between the primary site and the backup site.

Telecommunication: The telecommunication system was not a known brand to us, and the manufacturer informed us that the redundancy built into the system only works if both the primary and secondary were connected to the same switch infrastructure.

Solution Proposed

CrossRealms proposed a hot site solution in which three copies of the data and virtual machines will exist: one on their production systems, one on their local network in the form of a Cohesity Virtual Appliance, and one at our Chicago/Vegas Data Centers. This solution allows for instantaneous recovery using the second copy if their local storage or virtual machines are affected. Cohesity’s Virtual Appliance software can publish the environment instantaneously, without having to restore the data to the production system.

The third copy will be used in the case of a major fiber outage or power failure, where their systems will become operational at either of our data centers. The firewall policies and VPN tunnels are preconfigured – including having a read-only copy of their Active Directory environment – which will provide up-to-the-minute replication of their authentication and authorization services.

The following are items still in progress:

  • LAN Extension for their EMR: We have created a LAN Extension to one of their clinics which will help in case of a hardware or power/cooling failure at their primary facility. However, the vendor has very specific hardware requirements, which will force the hospital to either purchase and collocate more hardware at our data center, or migrate their secondary equipment instead.
  • Telecom Service: They currently have ISDN backup for the system, which will work even in the case of a fiber outage; once the ISDN technology is phased out in the next three years, an alternative needs to be configured and tested. Currently there will be no redundancy in case of primary site failure, which is a risk that may have to be pushed to next year’s budget.

Lessons Learned

The following are our most important lessons learned through working with this client:

  • Bringing management on board to push and prod vendors to work with the Business Continuity Team is important. We spent months attempting to coordinate testing the EMR system with the vendor, and only when management got involved did that happen.
  • Testing the different scenarios based on the tabletop exercises exposed issues that we didn’t anticipate, such as the fact that their primary storage was Solid State. This meant the backup solution had to incorporate the same level of IOPS, whether local to them or at our data centers.
  • Run books and continuous practice runs were vital, as they are the only guarantee of an orderly, professional, and expedient restoration in a real disaster.


Jul 11, 2019 by Sam Taylor

Amidst a news cycle rife with malware incidents and cyberattacks, there is one shining spot of hope: 100,000 malware sites have been reported and taken down within the last year., a non-profit cybersecurity organization, has spearheaded a malicious URL hunt known as the URLhaus intiative. First launched in March 2018, a small group of 265+ security professionals have been searching for sites that feature active malware campaigns. These reported sites are passed down to information security (infosec) communities, who work to blacklist or take down URL’s completely.

While abuse reports are rolling in, there has been slow action on the web hosting provider’s part. Once a provider has been reported to have a malicious site, they need to take action in removing or altering the site. Average times to remove the malware infected site has been reported to be 8 days, 10 hours, and 24 minutes– a generous time delay that allows the malware to infect even more end users.

Heodo is one of the most popular malwares used, a multi-faced strain that can be utilized as a downloader for a variety of other attacks, acting as a spam bot, banking trojan, or a credentials swiper.

While sites aren’t responding with a particular deftness, it is still quite a feat to gather all these malicious URL’s with the power of such a limited group of researchers.


Jul 11, 2019 by Sam Taylor

This past month one of our clients experienced a security compromise with their phone system, where 3 extensions had their credentials swiped. Among the information taken was the remote phone login information, including username, extension and password for their 3CX phone system.

Our first tip off of the attack was the mass amount of international calls being made. We quickly realized that this was not your traditional voicemail attack, or SIP viscous scanner attack because the signature of it was different (more below). To alleviate the situation we immediately changed their login credentials, but to our surprise the attack happened again with the same extensions within minutes of us changing their configuration.

For those of you thinking that the issue can be related to a simple or easy username and password (extension number and a simple 7-digit password), that wouldn’t be the case here. It’s important to note that with 3CX version 15.5 and higher, the login credentials are randomized and do not include the extension id, which makes it a lot harder to guess or brute force attack.

We locked down International dialing while we investigated the issue, and our next target was the server’s operating system. We wasted hours sifting through the logs to see if there were any signs of attack, but absolutely none were present. We next checked the firewall and again saw no signs of attack– so how was this happening? How were they able to figure out the user ID and password so quickly and without triggering the built-in protections that 3CX has, like blacklisting IP addresses and preventing password guessing attempts?

Right back to square one, we needed more information. After contacting different contacts of the client, we found out that the three extensions were present at an International venue, which interestingly enough, was the target of all the International calls!!! Phew, finally a decent clue. Under the assumption of a rogue wireless access point present at the hotel, we asked them to switch to VPN before using their extension, which stopped any new authentication fields from being guessed  – – –

While we were able to get our client up and running again, there was something a bit more interesting going on here. The hackers were using a program to establish connections and then use those connections to allow people to dial an International country on the cheap (margins here are extraordinary). That program is using an identifier “user_agent” when establishing a connection to make the calls. If we filter for that, they will have to redo their programming before they can launch the attack again, which proved to be a quick and instantaneous end to this attack irrespective of source– even if they acquire the necessary credentials.

Here’s how I would deal with this next time, in 3CX you can follow the following steps:

Go to

  1. Settings
  2. Parameters

3. Filter for “user_agent”

4. Add the user agent used (The Signature) in the attack to either fields and restart services

Eg. The Signature (Ozeki, Gbomba, Mizuphone)


Jul 11, 2019 by Sam Taylor

Microsoft JET Database Engine is left unpatched.

Microsoft JET, a database engine, is currently a massive vulnerability. A recent repair has yet to repair a long-standing flaw, leaving an opening for hackers.

JET is one of Microsoft’s first database engines, created in the 90’s, used to power a variety of Microsoft applications like: Microsoft Project, Visual Basic, an Access. It has since been phased out by newer technologies, but is still included in Window’s package for sentimental reasons.






The vulnerability had reached zero- day at the time of it’s announcement. Once a Microsoft encounters a vulnerability there is a 120 day window to complete a patch, failure would require a public announcement, known as zero day. This vulnerability has been declared public so users can take cautionary action and look to protect themselves from possible attacks. It has been rated as “2 – Exploitation Less Likely”, as a hacker could exploit the opening by altering data within the database.

An attacker would target a user by sending an email with a clickable link/ attachment that would allow access to the database. The link would be a specific JET Microsoft Database file that would require opening or importing the linked data. With access to the database the hacker would be able to alter or delete data.



How to Protect Yourself


As reported on earlier, don’t open links from emails sent from unknown sources. It is unclear if Microsoft will work to patch the vulnerability.


Jul 11, 2019 by Sam Taylor
Google+ has hidden a data breach for the past 6 months in order to avoid a larger fallout.

In response to a publicized security breach, Google is looking to shut down their failed social media site. Google+ was created with the intention of overthrowing Facebook, but instead has left its scanty user base exposed to third-party data intrusions via software bug.

How Data Was Compromised

Destined to be a popular site, Google+ was once an exclusive social media alternative that required an invitation, which made it all the more alluring; how users data was then shared with others is less exclusive. When signing into apps, there was the option to sign in with Google+,  similar to signing into an app with Facebook, which then allowed the app to collect and harvest data generated by the user. When a Google+ user logged in with their account, they not only offered up their information, but also their friend’s information.

Who Was Affected

While Google+ never experienced the fame it had predicted, there was still a notable user base. 500,000 users were ultimately affected by this security bug, which revealed their age, jobs, and local information– placing them in danger of fraud. The software bug gave approximately 438 third-party vendors access to users private information from 2015 to March 2018, when the loophole was discovered.

Why Was it Not Made Public

The Google+ data leak was discovered in March– incidentally the same month that Facebook was under fire for the Cambridge Analytica scandal. Looking to avoid Facebook’s fate, Google+ chose not to disclose the data leak– instead choosing to quietly repair the software bug. The difference in data leaks is rather apparent, with Google+ having a much smaller user base in comparison to Facebook.

What You Can Do

Many users made a Google+ account when it was all the rage, but most didn’t use it after initial creation. While you may not be using Google+ anymore, one of your friends might have– leaving you exposed. Checking to see if you have a Google+ account is as simple as checking your gmail or university email, then going into your settings to completely delete the Google+ account. A lot users have an account and they don’t even realize it.

The site is said to shut down in ten months, while leaving a business aspect of Google+ still available.


Jul 11, 2019 by Sam Taylor
Could Your Wi-Fi Router Be The Death of You?

Can my wi-fi router be compromised?

Wi-Fi routers pose an easy target for most hackers. A router’s firmware will pose a risk if left running without an update. Most households will keep their Wi-Fi router running day in and day out, without being checked for the latest patches or bug fixes.

Over time, Wi-Fi routers’ vulnerabilities are amplified. Most firmware is built with open source code, which is a cost-effective way to allow for customization, but is also seen as more susceptible to cyber attacks.

Is this even a serious threat?  

Yes. In a study done by the American Consumer Institute (ACI), it was found that in a range of 186 Wi-Fi routers, from a slew of popular providers, 155 were found to be based on open source code. This means that 83% of those routers have a higher probability of being exposed to attacks.

Earlier this year there were thousands of Wi-Fi routers infiltrated by Russian hackers, reported by NBC. Barreling through little protection, a semi-experienced hacker could easily move past password barriers such as: 1234 and other simple passwords. Once they have access to your router, they can sift through private data, spy on web interactions, or even gain access to your financial institutions.  

How to protect yourself:

  1. Update your Router’s firmware
  2. Search online for vulnerabilities on your device
  3. Turn off Remote Administration

While the “Remote Admin” tool is helpful for when you need tech help from afar, it leaves a loophole that could be used by hackers.


Jul 11, 2019 by Sam Taylor

A long day out would most likely mean that your phone is low on juice. In the distance you spot a charging station, with new stations even providing the ability to place a phone in a compartment and lock your phone, it’s even more enticing to charge your phone. Plugging your phone into these ports might cost you more than you would expect: your identity.

What is Juice Jacking?

Juice Jacking is the transfer of not only energy, but spyware onto your device using any public charging station. Any device can be compromised, from a blackberry to an Android, or even a Apple product. The spy software can find its way onto your phone through the cord used for energy transfer.

Negatively impacting a phone via juice jacking takes a matter of minutes. Within no time a hacker could have access to all sensitive data and photos on your personal device.

How to Protect Yourself

We’ve identified the cause of the issue: the cord connecting your phone to the charging station. To prevent future regret it would be best to:

  1. Carry your own power bank
  2. Carry a “energy only” USB cord
  3. Carry your own AC adapter if not using an “energy only” USB cord
  4. Only use electrical sockets
  5. Put passwords on apps to further protect data


Been Hacked By a Juice Jacker?

It’s best to fix the issue immediately before your data is further compromised. After finding the issue, it is also recommended to report the scammer to the FTC, here.  

Juice Jacking has been around since 2011, with lots of media coverage. CBS has covered this spyware recently: 


Jul 11, 2019 by Sam Taylor
Spear Phishing is known for making more calculated attacks, focusing on a smaller number of targets.

We all know about email phishing, it’s relatively easy to spot. When the prince of Nigeria emails asking for help, we know not respond with our banking info, but when your I.T. provider “emails” with a link to click to login, this might be a little harder to recognize as an attack. Spear phishing is the next worst version of plain old phishing.

Spear phishing is a relatively cheap and effective way to gain access to someone’s personal information or computer system. With a little research and an email address, a hacker can pose as a trusted source. Posing as this official source, hackers can access aia a spoofed login link or an attachment.

This type of phishing has increased by 65% since last year, meaning your inbox may soon receive an email you weren’t expecting. Here are a few examples of what a spear phishing attack may look like:

The Executive

Emails from higher-ups are always more likely to receive special attention, something hackers realize too. An American steel company was targeted with an email from the board of directors, which prompted employees to click a link. This link allowed for hackers to gain access to employee’s email database and all attachments.

Protect yourself from dubious links by double checking with the person who initiated the email. It is unlikely that there will be a login link attached in an email, but always double-check.

The Job Candidate

With team expansions come new hires, but not all job applicants are alike. This “potential” hire will typically send a short intro summary and an attachment of their resume, which is what holds this compromising malware.  

Protect yourself from malicious attachments by having an intermediary defense system, like a web portal or file uploader to scan all attachments to verify a word document.  

The IT Note

Who hasn’t run into IT troubles? When an email pops up from your provider, it doesn’t signal any red flags, but they link they provide might be anything but helpful.  

Protect yourself from these malicious links by remaining vigilant online and refraining from providing personal information online.

Remaining Vigilant Online

There are many ways for a hacker to investigate a user’s personal interests, such as through their social media. With simple research, a personally crafted attack could be sent to an unexpecting inbox. Don’t be the one to fall for the attack:


  1. Remain very vigilant online
  2. Double check with the sender
  3. Have an intermediary defense system
  4. Avoid links that direct to a login page
  5. Keep up to date with cyber attacks