Tag Archives: Corporate Security

Researching the recent Windows CTF Vulnerabilities

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TL DR
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There are no known mitigations for these vulnerabilities. Please see below for a more in-depth explanation.
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With the release of a security updates by Microsoft in September and August to resolve vulnerabilities in the Windows ALPC and Windows Text Service Framework I wish to provide details on these vulnerabilities.

Why should these vulnerabilities be considered important?
If an attacker were to have ALREADY compromised a vulnerable Windows system, they can then use the exploits made available by Google’s Tavis Ormandy to fully compromise your system. They can obtain the highest level of privilege on it namely NT Authority\System (equivalent to root on a Linux system).

Ormandy found that the running ctfmon.exe of Windows allowed a standard user of Windows to hijack any Windows process even if that process was sandboxed within an AppContainer (a means of isolating sensitive/important processes making them harder to attack). When an attacker does so they can obtain administrative and under some circumstances NT Authority\System level access.

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-1162

https://portal.msrc.microsoft.com/en-us/security-guidance/advisory/CVE-2019-1235

How I can protect my organization and myself from these vulnerabilities?
Apart from installing the above linked to updates, I’m afraid no other mitigations are available. You will need to exercise standard vigilance/caution with opening links. Don’t open attachments you weren’t expecting even from trusted contacts.

This advice is an unfortunate outcome. I had a hypothesis that disabling the ctfmon.exe process (Windows XP, Windows Vista and Windows 7) or the Touch Keyboard and Handwriting Panel service in Windows 8.1 and 10 would mitigate this class of vulnerabilities. This was not the case, Ormandy’s tool worked regardless of whether the ctfmon.exe process was running or not, which now makes sense given how his tool exploits a deeply integrated feature of Windows with a scope much larger than that of the above mentioned process and service.

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Proof of Concept
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As a proof of concept on an un-patched version of Windows 10 Version 1903, I can confirm Tavis Ormandy’s CTFTool successfully provides you with both System and Administrative (depending on the type of exploit you run). Only administrative access is available for Windows 7, the tool does not incorporate the System level exploit for Windows 7. Further details of this tool are available at the following links:

https://googleprojectzero.blogspot.com/2019/08/down-rabbit-hole.html

https://github.com/taviso/ctftool

Thank you.

September 2019 Update Summary

Today is the 2nd Tuesday of the month, when both Adobe and Microsoft routinely release their scheduled security updates.

Similar to last month Microsoft have released many updates resolving 79 vulnerabilities more formally known as CVEs (defined). It was a light month for Adobe releasing 2 updates resolving 3 vulnerabilities.

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Adobe Application Manager: 1x Priority 2 vulnerability resolved (Important severity)
Adobe Flash Player: 2x Priority 3 vulnerabilities resolved (Critical severity)

If you use either of these Adobe products, please install the necessary updates as soon as possible prioritising the Adobe Flash Player update.
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This month’s list of Known Issues from Microsoft is available within their monthly summary page and applies to all currently supported operating systems. Almost all issues have workarounds at this time and none appear to be serious issues. The up to date list is available from their summary page.

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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 SoftwareSecurity 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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For this month’s Microsoft updates, I will prioritize the order of installation below:
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Microsoft Windows LNK Remote Code Execution Vulnerability: CVE-2019-1280

Microsoft Scripting Engine: CVE-2019-1298

Microsoft Scripting Engine: CVE-2019-1300

Microsoft Scripting Engine: CVE-2019-1217

Microsoft Scripting Engine: CVE-2019-1208

Microsoft Scripting Engine: CVE-2019-1221

Microsoft Scripting Engine: CVE-2019-1237

Windows RDP: CVE-2019-1291

Windows RDP: CVE-2019-1290

Windows RDP: CVE-2019-0788

Windows RDP: CVE-2019-0787

Team Foundation Server/Azure DevOps: CVE-2019-1306

Microsoft Office SharePoint: CVE-2019-1295

Microsoft Office SharePoint: CVE-2019-1257

Microsoft Office SharePoint: CVE-2019-1296

Common Log File System Driver (defined): CVE-2019-1214

Microsoft Windows Elevation of Privilege Vulnerability (defined): CVE-2019-1215

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Please install the remaining updates at your earliest convenience.

As per standard best 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.

I have provided further details of updates available for other commonly used applications below.

Thank you.

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Mozilla Firefox
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On September the 3rd Mozilla released Firefox 69.0 to address the following vulnerabilities and to introduce new privacy features:

Firefox 69.0: Resolves 1x critical CVE (defined), 11x high CVEs, 4x moderate and 3x low CVEs

Firefox ESR 68.1 (Extended Support Release): Resolves 1x critical, 9x high, 4x moderate and 2x low CVEs

Firefox 60.9 ESR : Resolves 1x critical CVE, 7x high CVEs and 1x moderate CVE

Highlights from version 69 of Firefox include:
Blocks 3rd party cookies and cryptominers (using Enhanced Tracking Protection) by default (blocking of fingerprinting scripts will be the default in a future release)

Adobe Flash disabled by default (must be re-enabled if needed)

Separately Mozilla is facing criticism over their plans to gradually roll-out DNS over HTTPS (DoH) later this month since all DNS traffic would go to only one provider, Cloudflare. Google Chrome will implement a similar feature soon (further details are available in the above link also regarding Mozilla).

Details of how to install updates for Firefox are here. If Firefox is your web browser of choice, if you have not already done so, please update it as soon as possible to benefit from the above changes.

Thank you.

Mitigating August’s Remote Desktop Services (RDS) Vulnerabilities

Earlier last week Microsoft released security updates for Remote Desktop Services (RDS).

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TL DR:
If you use  Windows 7 SP1, Windows Server 2008 R2 SP1, Windows Server 2012, Windows 8.1, Windows Server 2012 R2, and all supported versions of Windows 10, including server versions, please install the security updates for August 2019 which include fixes to these vulnerabilities: CVE-2019-1181 and CVE-2019-1182
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Why should these vulnerabilities be considered important?
The following two vulnerabilities CVE-2019-1181 and CVE-2019-1182 have received a CVSS 3 base score (defined) of 9.8 and have the potential to be used by network worms to rapidly spread without the need for assistance from computer users. There is the potential for a repeat of an attack very similar to the WannaCry ransomware outbreak of May 2017.

How can I protect my organisation or myself from these vulnerabilities?
The most effective means of defence is to install the updates released by Microsoft available via Windows Update (this link provides guidance on doing so) or manually from the above links.

While the BlueKeep vulnerability has not yet been exploited, there are indications (here and here) it may be soon. These more recent vulnerabilities will likely receive similar or more interest since they are present in more versions of Windows (8.1 and 10 alongside their Server based equivalents) than BlueKeep.

If for any reason this is not possible, the mitigations listed in this Microsoft blog post will be useful. Thank you.

August 2019 Update Summary

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Update: 13th August 2019
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Earlier today Adobe and Microsoft released large collections of security updates. They resolve 119 and 93 vulnerabilities (respectively).

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Adobe After Effects: 1x Priority 3 vulnerability resolved (Important severity)

Adobe Character Animator: 1x Priority 3 vulnerability resolved (Important severity)

Adobe Premiere Pro CC: 1x Priority 3 vulnerability resolved (Important severity)

Adobe Prelude CC: 1x Priority 3 vulnerability resolved (Important severity)

Adobe Creative Cloud Application: 4x Priority 2 vulnerabilities resolved (2x Critical and 2 Important severity)

Adobe Acrobat and Reader: 76x Priority 2 vulnerabilities resolved (76x Important severity)

Adobe Experience Manager:1x priority 1 vulnerability resolved (1x Critical severity)

Adobe Photoshop CC: 34x priority 3 vulnerabilities resolved (22x Critical and 12x Important)

If you use any of these Adobe products, please apply the necessary updates as soon as possible especially for Adobe Acrobat/Reader, Photoshop CC and Experience Manager

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This month’s list of Known Issues from Microsoft is available within their monthly summary page and applies to all currently supported operating systems. Not all issues have workarounds at this time. The up to date list is available from their summary page. For Windows 7, for customers with Symantec Antivirus or Norton Antivirus, a hold has been put on the updates from being offered in Windows Updates due to ”The Windows updates are blocked or deleted by the antivirus program during installation, which may then cause Windows to stop working or fail to start”. The Symantec article linked to at this time is a blank template.

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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 SoftwareSecurity 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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For this month’s Microsoft updates, I will prioritize the order of installation below:
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Microsoft Remote Desktop Services (RDS):  CVE-2019-1181 CVE-2019-1182  CVE-2019-1222, and CVE-2019-1226 (CVE, defined)

Microsoft Graphics Component CVE-2019-1144  CVE-2019-1152  CVE-2019-1150 CVE-2019-1145 CVE-2019-1149

Microsoft Word CVE-2019-1201 CVE-2019-1205

Microsoft Outlook CVE-2019-1200 CVE-2019-1199

Scripting Engine CVE-2019-1133

Chakra Scripting Engine CVE-2019-1141 CVE-2019-1131 CVE-2019-1196 CVE-2019-1197 CVE-2019-1140 CVE-2019-1139

LNK Remote Code Execution Vulnerability CVE-2019-1188

Windows DHCP Client CVE-2019-0736 CVE-2019-1213

Windows Hyper-V CVE-2019-0720 CVE-2019-0965

Windows VBScript Engine CVE-2019-1183

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Please install the remaining updates at your earliest convenience.

As per standard best 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.

I have provided further details of updates available for other commonly used applications below.

Thank you.

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Mozilla Firefox
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In mid-August Mozilla released Firefox 68.0.2 and Firefox ESR 68.0.2 to resolve a moderate information disclosure vulnerability. Please make certain your installation is version 68.0.2 or above to resolve this issue.

Details of how to install updates for Firefox are here. If Firefox is your web browser of choice, if you have not already done so, please update it as soon as possible to benefit from the above changes.

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Google Chrome
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In late August the Centre for Internet Security released a security advisory for users of Google Chrome to update to version 76.0.3809.132 or later. Prior versions were vulnerable to a use-after-free (defined) vulnerability which could have allowed remote code execution (allowing an attacker to carry out any action of their choice).

Google Chrome updates automatically and will apply the update the next time Chrome is closed and then re-opened. Chrome can also be updated immediately by clicking the Options button (it looks like 3 stacked small horizontal lines, sometimes called a “hamburger” button) in the upper right corner of the window and choosing “About Google Chrome” from the menu. Follow the prompt to Re-launch Chrome for the updates to take effect.

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VMware
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VMware earlier this month released a security advisory to resolve 2 Important severity vulnerabilities within the following products:

VMware vSphere ESXi (ESXi)
VMware Workstation Pro / Player (Workstation)
VMware Fusion Pro / Fusion (Fusion)

An attacker could leverage the vulnerability CVE-201-5521 (from the above linked to advisory) to also exploit CVE-2019-5684 to exploit Nvidia’s GPU driver (see below) to gain arbitrary code execution on a system.

If you use the above VMware products particularly with a Nvidia GPU, please review the advisory and apply the necessary updates.

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Nvidia
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Nvidia late last week issued a related security advisory to that of the above VMware advisory. Nvidia’s advisory resolves 5 locally exploitable vulnerabilities meaning that an attacker would first need to compromise your system before exploiting the vulnerabilities to elevate their privileges (defined). The steps to install the drivers are located here. If you use affected Nvidia graphics cards, please consider updating your drivers (defined) to the most recent available.

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Canon Digital Cameras PTP (Picture Transfer Protocol) Vulnerabilities
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Canon digital cameras utilising this protocol are potentially vulnerable to a complete takeover of the device while connected to a host PC or a hijacked mobile device.

As per this Canon advisory, please ensure your camera is using the most recent firmware update and that you follow the workarounds listed in the above advisory.

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VideoLAN VLC
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On the 19th of August, VideoLAN released VLC version 3.0.8 resolving 13 security issues (some assigned more than one CVE). In a recent presentation their President, Jean-Bapiste Kempf explains the challenges they face in maintaining the security of the project. The short slide deck gives a behind the scenes look at their work including the tools they use to make their code safer.

The list of challenges isn’t too dissimilar from a regular commercial company e.g.: a complex piece of software (15 million lines of code) with approximately 100 dependencies but does highlight issues with hostile bug bounty hunters etc. Future releases will include security bulletins where relevant.

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Valve Steam Gaming Client
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In late August, Valve released 2 security updates for their Steam gaming client. Further information on the disclosure (defined) is detailed here while details of the updates are available here and here (albeit in summary only). The Steam client by default updates automatically. Please open it and allow it to update to resolve these vulnerabilities.

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Software Updates for HP , Lexmark, Kyocera , Brother , Ricoh and Xerox Printers
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The following links details the vulnerabilities found by security researchers within these printers and link to the relevant software updates:

HP
https://www.nccgroup.trust/us/our-research/technical-advisory-multiple-vulnerabilities-in-hp-printers/?research=Technical+advisories

Lexmark
https://www.nccgroup.trust/us/our-research/technical-advisory-multiple-vulnerabilities-in-lexmark-printers/?research=Technical+advisories

Kyocera
https://www.nccgroup.trust/us/our-research/technical-advisory-multiple-vulnerabilities-in-kyocera-printers/

Brother
https://www.nccgroup.trust/us/our-research/technical-advisory-multiple-vulnerabilities-in-brother-printers/

Ricoh
https://www.nccgroup.trust/us/our-research/technical-advisory-multiple-vulnerabilities-in-ricoh-printers/

Xerox (PDF)
https://securitydocs.business.xerox.com/wp-content/uploads/2019/08/cert_Security_Mini_Bulletin_XRX19R_for_P3320.pdf

https://www.nccgroup.trust/us/our-research/technical-advisory-multiple-vulnerabilities-in-xerox-printers/

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Security Updates for Corporate and Consumer 4G Modems
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G Richter a security researcher from Pen Test Partners disclosed the following vulnerabilities during DEF CON:

Netgear
Netgear Nighthawk M1 Mobile router (currently no vendor advisory):
Cross-site request forgery (CSRF)(defined) bypass: CVE-2019-14526
Post-authentication command injection: CVE-2019-14527

TP-Link
TP-Link’s M7350 4G LTE Mobile wireless router (currently no vendor advisory):
CVE-2019-12103 – Pre-Authentication Command Execution
CVE-2019-12104 – Post-Authentication Command Execution

ZTE
MF910 and MF65+ Advisory
http://support.zte.com.cn/support/news/LoopholeInfoDetail.aspx?newsId=1010203

MF920 Advisory
http://support.zte.com.cn/support/news/LoopholeInfoDetail.aspx?newsId=1010686

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HTTP/2 Vulnerabilities
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8 HTTP/2 DoS (defined) vulnerabilities have been responsibly disclosed by Netflix and Google. According to CloudFlare these vulnerabilities are already being exploited “We have detected and mitigated a handful of attacks but nothing widespread yet”.

Please review the affected vendors matrix within the following CERT advisory and apply the necessary updates:

https://kb.cert.org/vuls/id/605641/

Further information
https://github.com/Netflix/security-bulletins/blob/master/advisories/third-party/2019-002.md

https://www.theregister.co.uk/2019/08/14/http2_flaw_server/

https://www.bleepingcomputer.com/news/security/new-http-2-flaws-expose-unpatched-web-servers-to-dos-attacks/

Thank you.

Mitigating the Intel SWAPGS Vulnerability

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TL DR
This is medium severity information disclosure vulnerability. An attacker must already have compromised a system to exploit it. Patches from Red Hat, Google and Microsoft are available. Apple hardware does not appear to be affected.
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If we look back 2 weeks we saw the disclosure of a vulnerability relating to VideoLAN VLC being performed incorrectly. This week there is an example of how responsible disclosure should be carried out and demonstrates it can work very well.

Red Hat Linux, Google and Microsoft have all issued patches for a newly discovered variant of the original Spectre v1 vulnerability (initially disclosed in January 2018).

The performance impact of the updates is described in the Red Hat advisory in more detail:

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The fix for this CVE has shown to cause a minimal performance impact. The impact will be felt more in applications with high rates of user-kernel-user space transitions. For example, in system calls, NMIs, and kernel interrupts.

Early benchmarks for this mitigation show approximately 1% performance penalty:

https://www.phoronix.com/scan.php?page=article&item=swapgs-spectre-impact&num=1
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How does this vulnerability work?
When building a memory address to access computer make use of segment registers (CS, DS, SS, ES, FS, GS). The FS and GS registers are used when the CPU (defined) is in 64-bit mode. The SWAPGS instruction is used on 64-bit entry into kernel code to swap the current user space value of GS with the value intended to be used during kernel operations. GS is used to access kernel data, but it does not validate the values it uses. There are checks during instruction execution to check if a swap to kernel mode is necessary. It is possible for the speculative execution process (attempting to look ahead to improve performance) to mis-judge if a swap is necessary  resulting in a small window of time where the wrong GS is used for memory access leading to disclosure of privileged information.

How can I protect my organisation and myself from this vulnerability?
Earlier this week Red Hat and Google released updates to resolve this vulnerability. Microsoft issued their update silently on 9th July:

Red Hat Linux
https://access.redhat.com/articles/4329821

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=18ec54fdd6d18d92025af097cd042a75cf0ea24c

Google Chrome OS
https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/1739575

Microsoft Windows
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-1125

Thank you.

IBM Creates “Warshipping” Proof of Concept Device

Earlier this year I detailed a new method for an attacker to compromise an organisation by means of a modified smartphone charging cable. Today we see another method to compromise an organisation using an even more common means; the postal mail.

Why should this attack method be considered important?
Virtually every organisation receives postal mail with packages being commonplace. An attacker could send an anonymous package with one of the devices the IBM X-Force team created. The device was a small motherboard (defined) with 3G, WiFi and GPS built-in. It can be activated remotely over the internet and report its position via GPS and then instructed to scan for vulnerable network devices to attack.

It’s used to obtain the credentials of a corporate WiFi network. Once complete the device seeks to pivot using other vulnerable devices on the network to eventually compromise the network (also achieving persistence) and exfiltrate data or any other action of the attacker’s choice.

An attacker no longer needs to scout premises before trying to infiltrate it. They can just send a parcel to do it for them.

How can I protect my organisation or myself from this?
For an organisation; you can prohibit employees from having personal packages shipped to their office. A much more rigorous and expensive option which is unlikely to be favoured would be to scan all deliveries with an RF scanner.

Other suggestions to counter this device are detailed in IBM’s blog post.

Thank you.

Wind River Resolves Critical Infrastructure Vulnerabilities

Last week the real-time embedded systems vendor Wind River Systems released security updates for a large number of critical infrastructure systems.

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TL DR:
If any of your enterprise clients use within their network perimeter: modems, routers, firewalls, printers, industrial control or medical monitoring devices; check if any of those devices use Wind River’s VxWorks software based on their TP/IP stack (IPnet). If so, review the FAQs and security advisory linked to below to install the necessary updates.
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Why should these vulnerabilities be considered important?
The sheer number of affected devices is thought to be very large due to the prevalence of devices running the vulnerable VxWorks software. I realize the list of devices above is very generic but the FAQs and security advisory are not vendor or model specific. This means you may have some of these devices and not even realize it. Verifying if they are using VxWorks and what version will be a priority.

Since medical monitoring and industrial control devices are included in this advisory; if these vulnerabilities are exploited there is the potential for a threat to human life. E.g. if incorrect results are displayed on a medical device, too much medication is administered, or if temperatures exceed safe levels in an industrial control system.

Due to the nature of four of the vulnerabilities; a border firewall will not always be enough to prevent an attacker exploiting. Broadcast packets could be sent to every device in the network, compromising them all at once.

How can I protect my organization from these vulnerabilities?
Review the FAQs and the security advisory and take the necessary steps to install the relevant patches. If your organisation is affected; first apply the necessary mitigations to any vulnerable device you initially discover while you assess the remaining number of impacted devices and develop a plan/schedule to approach the installation of the patches:

Mitigations listed on Page 3 (onwards) of this security advisory:
https://www.windriver.com/security/announcements/tcp-ip-network-stack-ipnet-urgent11/security-advisory-ipnet/

FAQs:
https://www.windriver.com/security/announcements/tcp-ip-network-stack-ipnet-urgent11/ipnet-faq/

From my understanding of the information provided by Wind River they are directly contacting their affected clients and may offer paid for assistance to resolve these vulnerabilities for out of support devices. However, there is a possibility they may inadvertently miss an affected organisation. Please contact Wind River if in doubt:

support@windriver.com

Thank you.

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References:
Wind River’s Blog Post:
https://blogs.windriver.com/wind_river_blog/2019/07/urgent-11-further-boosts-vxworks-security.html

Kaspersky ThreatPost article:
https://threatpost.com/urgent-11-critical-infrastructure-eternalblue/146731/
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