Monthly Archives: January 2020

Blog Post Shout-out: Potential for Ransomware to Leverage Windows EFS

Related to my previous post detailing my tests of anti-ransomware software that could compliment existing anti-malware software, I wish to provide a respectful shout-out to the following post from SafeBreach. It details their results testing a proof of concept of using the built-in Encrypting File System (EFS) capability of Windows in order to encrypt a victim’s files rather than writing their own means of doing so:

https://safebreach.com/Post/EFS-Ransomware

Please review the list of anti-malware and anti-ransomware solutions available within the SafeBreach post. If yours is not on the list, contact the vendor to ask if such a change will be added soon? If you are certain you will not being EFS, disable it using the Windows Registry (defined) changes suggested in their post.

Thank you.

Cable Modems Vulnerable to Cable Haunt Vulnerabilities

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TL;DR
If you are cautious with the links you click and when processing your email, you will likely not be vulnerable to these flaws. If you use a cable modem for your internet connection, you should check if your modem is vulnerable and follow the step “What should I do” mentioned below.
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In mid-January it was discovered the firmware (defined) of many internet service provider (ISP) modems (specifically combined modems and routers in the same device) was vulnerable to remote takeover by attackers. These vulnerabilities have been named Cable Haunt as an easier to remember reference.

How widespread are the affected modems?
At the least the following manufacturers are affected with up to 200 million vulnerable modems mainly based in Europe but other regions e.g. North America are also affected. Please see also the FAQ “Am I Affected” on the Cable Haunt website.

Arris
COMPAL
Netgear
Sagemcom
Technicolor

Other brands of modems confirmed by the wider community as being vulnerable are:

Cisco EPC3928AD
Cisco/Technicolor DPC3216
Humax HGB10R-02
SMC Electronics SMC D3-CCR-v2
Zoom 5370
Virgin Media’s Super Hub 3 and 4 do not appear to be vulnerable.

How serious are these vulnerabilities?
While the vulnerabilities are serious in their impact, namely complete remote compromise of the device, how an attacker could exploit the vulnerabilities to achieve that outcome is not trivial. As per the researchers:

“This could be exploited by an attacker if you visit a malicious website or if they embed the code, for instance in an advert, on a trusted website. It is important to point out that this is not the only attack vector that can be employed, vulnerable mail-clients, exploited IoT devices, public networks etc. are also viable attack vectors”.

Summary of the Technical Aspects of these vulnerabilities
The vulnerability designated formally as CVE-2019-19494 is a buffer overflow (defined) that if exploited could allow remote code execution (defined: the ability for an attacker to remotely carry out any action of their choice on your device) with kernel level (defined) privileges by using JavaScript (defined) within your web browser. The buffer overflow can be exploited using (according to the researchers: “a carefully crafted message the modem can be manipulated to execute arbitrary code specified by a remote attacker”.

An important aspect of the above described exploit is that while the attack is a remote attack (using a victim’s web browser) it results in the local compromise of the modems spectrum analyser. Linked to this; a DNS re-bind attack (defined) can be used to enable an attacker the ability to access the compromised spectrum analyser. The result of the above exploits provides the attackers with (according to the researchers): “full remote control over the entire unit, and all the traffic that flows through it, while being invisible for both the user and ISP,”. This capability could be used to:

  1. Intercept private messages
  2. Redirect traffic
  3. Add the modems to botnets
  4. Replace the devices firmware
  5. Instruct the device to ignore remote system updates (which could be used to patch the vulnerabilities, complicating the resolution of a compromised device by its legitimate owner/user)

How can I protect my organisation or myself from these vulnerabilities?\
For in-depth answers from the researchers to answer this question in the context of an internet service provider (ISP), the user of the modem (e.g. within a small business), as an individual or a security researcher, please see the question “What Should I do” on the dedicated Cable Haunt website:

https://cablehaunt.com/

According to Graham Cluley: “Some ISPs in Scandinavia appear to have remotely patched the cable modems of their customers, but others have some catching up to do it seems.
If your cable modem contains a Broadcom chipset you might want to contact your ISP and ask them what they’re doing about this”.

Thank you.

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My sincere thanks to the Cable Haunt researchers Alexander Dalsgaard Krog (Lyrebirds), Jens Hegner Stærmose (Lyrebirds), Kasper Kohsel Terndrup (Lyrebirds) and Simon Vandel Sillesen (Independent) as well as Graham Cluley for the excellent information which this blog post is built upon.

January 2020 Update Summary

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Update: 11th February 2020
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This Internet Explorer zero day (defined) vulnerability was resolved by the patch released by Microsoft today. If you use Internet Explorer (especially versions 8 or earlier), please install this update as soon as possible.

Thank you.

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Update: 27th January 2020
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Shortly after the release of Microsoft’s scheduled updates, on the 17th of January they issued a security advisory for a critical zero day (defined) vulnerability being exploited by attackers in targeted attacks.

An out of bound update has not been released by Microsoft since by default all support versions of Internet Explorer by default use Jscript9.dll rather than Jscript.dll However versions earlier then IE 9 face increased risk.

If you use Internet Explorer for day to day work or just general surfing, please consider implementing the workaround described within Microsoft’s security advisory. Please remember to remove the workaround prior to installing the relevant security update in February. Also, please note that this workaround is causing some printers not to print and the Microsoft Print To PDF function not to work. If this is the case, use another browser and disable the workaround or use the micropatch (discussed below).

An alternative which according to ghacks.net is free is to install the micro-patch for IE available from 0Patch. More information on the micropatch and how to install it is available in the previous link above. This micropatch does not come with side effects. A YouTube video of the micropatch in action is available from the following link:

https://youtu.be/ixpBN_a2cHQ

Thank you.

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Original Post
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Happy New Year to my dedicated readers!

Today Adobe and Microsoft released their first security updates of the year. Adobe resolved 9 vulnerabilities more formally known as CVEs (defined) with Microsoft addressing 50 vulnerabilities.

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Adobe
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Adobe Experience Manager: 4x Priority 2 CVEs resolved (3x Important severity, 1x Moderate severity)

Adobe Illustrator CC: 5x Priority 3 CVEs resolved (5x Critical severity)

If you use the above Adobe products, please install these updates (especially in the case of the above critical vulnerabilities within Illustrator CC).
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Inside Microsoft’s monthly summary; there are Known Issues for 9 Microsoft products but all have workarounds (some workarounds will be replaced by further updates).

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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/

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For this month’s Microsoft updates, I will prioritize the order of installation below:
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Windows CryptoAPI Spoofing Vulnerability: CVE-2020-0601 (disclosed by the NSA to Microsoft). Further information on this vulnerability is available from KrebsonSecurity, within this CERT advisory and the detailed NSA PDF.

Windows Remote Desktop Gateway (RD Gateway) Remote Code Execution Vulnerability: CVE-2020-0609

Windows Remote Desktop Gateway (RD Gateway) Remote Code Execution Vulnerability: CVE-2020-0610

Remote Desktop Client Remote Code Execution Vulnerability: CVE-2020-0611

.NET Framework Remote Code Execution Injection Vulnerability: CVE-2020 0605

.NET Framework Remote Code Execution Injection Vulnerability: CVE-2020-0606

.NET Framework Remote Code Execution Injection Vulnerability: CVE-2020-0646

Please install the remaining less severe updates at your earliest convenience.

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Microsoft Edge Chromium
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Tomorrow, 15th January will mark the release of a new version of Microsoft Edge powered by the Chromium rendering engine. This version will be available for Windows 7, 8.1 and 10. This is especially relevant for Windows 7, Windows Server 2008 and Server 2008 R2 since while Windows itself ends its support lifecycle today, Edge Chromium will continue to be supported for a further 18 months. This matches similar statements from Google regarding Chrome and separately Vivaldi.

For details of which versions of Windows 10 will receive the new Edge via Windows Update and which versions will need to download it separately, please refer to this link. I wish to extend my thanks to Softpedia and Bleepingcomputer.com for these really useful links.

If for any reason, you wish to use the previous version of Edge (which uses the legacy rendering engine, please see this link for details of how to run the older version alongside its modern equivalent).

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 early January Mozilla released new versions of Firefox to address the following vulnerabilities and to add new user privacy features:

Firefox 72.0: Resolves 5x high severity CVEs (defined), 5x moderate CVEs and 1x low CVE

Firefox ESR 68.4 (Extended Support Release): Resolves 4x high severity CVEs and 2x moderate CVEs

More recently Firefox 72.0.1 was released to address a single critical severity zero day (defined) vulnerability which was responsibly disclosed to Mozilla and fixed very quickly. Finally Firefox 72.0.2  was released on the 20th of January resolving inconsistent playback of full-screen HD videos among non-security other issues.

Highlights from version 72 of Firefox include:
In addition to picture in picture enabled by default for macOS and Linux, it blocks the use of fingerprinting by default (the collection of data from your system e.g. browser version, font size, screen resolution and other unique data. This protection is provided by Disconnect. There are multiple levels of fingerprinting protection provided with the standard level being enabled by default. The strict level however may lead to websites not functioning as expected. Further details are available here.

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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Wireshark
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In mid-January the following Wireshark updates were released:

v3.2.1: Relating to 1 security advisory

v3.0.8: Relating to 1 security advisory

As per standard process Linux distributions can obtain this update using the operating systems standard package manager (if the latest version is not installed automatically using the package manager you can instead compile the source code (v3.2.1 or v3.0.8). This forum thread and this forum thread may also be helpful to you with installing Wireshark on your Linux based system.

For Mac OS X and Windows, the update is available within the downloads section of the Wireshark website. In addition, a detailed FAQ for Wireshark is available here.

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Google Chrome
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Google made available two security updates during November; the first resolves 3 vulnerabilities while the second resolves 16 vulnerabilities. The second also provides mitigation for the vulnerability disclosed by the NSA to Microsoft more commonly known as the  Chain of Fools/CurveBall or CVE-2020-0601 This test page from SANS will then show your system is no longer vulnerable after applying the second update. Please still apply the update from Microsoft to provide the most protection, Google’s changes are a mitigation only.

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 vertically stacked dots) 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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Intel Security Advisories
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Intel have released a series of security advisories this month. The advisories are prioritised below. If you use any of these products, software or devices, please update them as soon as possible especially in the case of the high severity advisories:

High
Intel VTune Amplifier for Windows Advisory

Medium
Intel Processors Data Leakage Advisory
Intel Processor Graphics Advisory
Intel RWC 3 for Windows Advisory
Intel Chipset Device Software Advisory
Intel SNMP Subagent Stand-Alone Advisory for Windows

Low
Intel Data Analytics Acceleration Library (DAAL)

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VMware
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VMware released 2 security advisories in January , the first is of moderate severity with the second being of important severity. The advisories relate to the following products:

Moderate Severity Advisory:

Workspace ONE SDK

Workspace ONE Boxer

Workspace ONE Content

Workspace ONE SDK Plugin for Apache Cordova

Workspace ONE Intelligent Hub

Workspace ONE Notebook

Workspace ONE People

Workspace ONE PIV-D

Workspace ONE Web

Workspace ONE SDK Plugin for Xamarin

Important Severity Advisory:
VMware Tools

If you use the above VMware products, please review the advisories and apply the necessary updates.

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Oracle:
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Oracle issued updates to resolve 334 vulnerabilities in January 2020. Further details and installation steps are available here. 12 vulnerabilities affect the Java runtime; all of which are remotely exploitable without an attacker needing to obtain a user’s username and password (their credentials).

If you use any of the Oracle products listed here, please install the appropriate security updates as soon as possible.

Microsoft Ends Support for Windows 7, Server 2008 and Server 2008 R2

As you are likely aware, on Tuesday, 14th January Microsoft will end support for Windows 7, Windows Server 2008 and Windows Server 2008 R2.

Approximately, 27% of all Windows devices are using Windows 7 so many devices are potentially impacted.

For enterprise and organisations, please consider upgrading to a newer version of Windows. Further details of your options are available here (this link mentions newer versions of Windows Server after Windows Azure). For Windows 7 users, you can consider upgrading to Windows 10 or paying for extended security updates (for businesses and enterprises only). This article provides details of your options (my thanks to TechRadar for this article).

Application compatibility when migrating from Windows 7 to Windows 10 (or their Server equivalent) is very good. Microsoft (perhaps) conveniently states it at a 99% chance your applications will work without changes. For businesses they offer their Desktop App Assure service for assistance if a Windows 7 applications experiences issues on Windows 10.

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Update: 14th January 2020
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Further suggestions to better defend Windows 7, Windows Server 2008 and Windows Server 2008 R2 are the following (my thanks to itlab.com for this list):

  • Make the system offline only, if network access isn’t needed (take it off the wired or wireless network).
  • If network access is needed, put the system on a separate subnet and only permit access to and from it for authorized systems. Make sure to narrow the ports permitted to connect to and from this system so that only needed ports are open.
  • Remove all unnecessary apps and disable any unneeded services.
  • If the system is a virtual machine, take periodic snapshots of it, so if it becomes affected by a vulnerability, you can restore the snapshot easily.
  • Make certain this system is not permitted to access the internet unless it is necessary for functionality. Ensure a proxy server is in place and will only permit access to authorized sites.
  • Make sure the system has anti-malware software on it, and it’s regularly updated.

While Microsoft’s Extended Security Updates (ESU) paid for scheme applies to businesses of all sizes you may experience is fewer than 50 staff as evidenced by well known Microsoft blogger, Ed Bott in the his article. While further providers came forward after the article was published, please be aware that it may not be a simple process to be accepted for the scheme.

A practical list of Windows 7 FAQs is also available from here (my thanks to AskWoody.com for this)

Thank you.

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Further References:
Support for Windows 7 is nearing the end

Support for Windows 7 ends in January 2020 (links for business, enterprise and home users)