John Marrett

John is Stack8's Director of Managed Services. John specializes in network and security, by developing innovative solutions for our clients and providing them with ongoing support.

Recent Posts

CVE-2017-3881 How to Mitigate CIA Vault 7 Exploits on Your Cisco Switches

Posted by John Marrett on Mar 22, 2017 11:04:46 AM

The threat
Two weeks ago WikiLeaks released Vault 7, a large collection of documents that they claim were taken from the CIA. While the CIA has not confirmed this release, there's little question that the leaked information comes from a nation state level intelligence service and contains extensive details regarding exploits and tradecraft targeting a wide variety of service providers, vendors, and equipment. Wikileaks has thus far attempted to redact detailed exploit information and has announced their intention to work with the impacted parties to address these vulnerabilities.

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Topics: CVE-2017-3881, vault 7, cisco switches, IOS Telnet

Use of Scripting to Identify Devices Affected by the Clock Signaling Field Notice

Posted by John Marrett on Mar 13, 2017 2:03:43 PM

By now you have likely heard about the "Clock Signaling Component" issue affecting a broad range of Cisco products. If you haven't a number of Cisco products are affected by an issue that will cause them to fail during normal operation, once they fail they will stop functioning completely and can not be powered back on. You can learn more about the affected devices on the notice page

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Topics: UC managed Services, Cisco Clock Issue

Cisco WebEx Plugin Vulnerabilities Affecting Chrome, Firefox and Internet Explorer (CVE-2017-3823)

Posted by John Marrett on Jan 24, 2017 4:26:52 PM

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There is a severe bug in the WebEx extensions for Chrome, Firefox and Internet Explorer (CVE-2017-3823) that enables an attacker to execute arbitrary code on a machine if a user with the plugin installed visits a hostile website. A trusted website may also contain a hostile ad or XSS vulnerability that can be leveraged in this attack. This plugin is installed on approximately 10 - 20 million user machines.

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Topics: chrome, firefox, CVE-2017-3823, webex

Diagnosing Firewall "Misbehaviour" with Packet Captures

Posted by John Marrett on Jun 22, 2016 8:30:00 AM

Our support team received a call from a customer complaining that their next generation firewall (NGFW) was intermittently blocking access to their new voting website. As we were in the process of making firewall changes inside their environment and are responsible for the management of their network they turned to us for help.

The website was a vanity domain hosted at GoDaddy that redirected users to a deep link within another website. We accessed the site and confirmed that it was working properly and sending a 301 redirect as expected, it worked properly both inside their and our environment. We reviewed the firewall logs and found no indications that traffic was blocked by any firewall or IPS. The customer insisted that there was an intermittent problem accessing the website that seemed to affect some users at random.

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Topics: Network & Security Insights, Network

Cisco Cloud Services Router 1000v in Review

Posted by John Marrett on Apr 28, 2016 10:00:00 AM

 

The Cloud Services Router 1000v (CSR) is one of Cisco's best kept secrets in the routing and security space. The CSR is an incredibly powerful product that's flexible, adaptable and offers almost limitless functionality at a very low price point. In some cases, this router will cost less to license than the ongoing support costs of the traditional router that they could replace. While infrequently positioned in these roles by VARs and account teams the CSR is surprisingly capable.  In this blog post, we will review the advantages and limitations of the CSR in our experience using it on the routing and security side of the business although it's also starting to be used for some Unified Communications related roles.

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Topics: Cisco Unified Communications Insights, Network & Security Insights, Cisco Release Notes and Product Reviews

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