Author Archives: JimC_Security

Blog Post Shout Out: June 2018

A number of varied security issues have come to my attention this week which I wanted to keep you informed of. I will provide a respectable shout out to the following sources:

Apple Encrypted Drive Information Disclosure:
At this time Apple macOS has an information disclosure vulnerability that affects encrypted drives in general (encrypted Apple HFS+ / APFS+ and VeraCrypt) that provide the potential for an attacker to obtain details of the files an encrypted hard drive is storing.

This vulnerability originates from the quick look feature of macOS; which allows a user to preview photos, files and folders quickly without having to open them. This feature stores the thumbnails (defined) of the files centrally in a non-encrypted area of the hard disk. This issue can also occur when a USB memory drive is inserted; the same feature stores thumbnails on the external drive and on the boot drive of the macOS system.

If you use an encrypted hard disk or value your privacy when using external drives, please run the following command documented at the end of the following news article after you have viewed sensitive info and want to clear that history/activity:

macOS Breaks Your OpSec by Caching Data From Encrypted Hard Drives: BleepingComputer by Catalin Cimpanu

This suggestion is a workaround until (and if) Apple patches this.

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Yubico WebUSB Bypass:
The two-factor authentication/secure login vendor, Yubico has published a security advisory for the use of their YubiKeys. The vulnerability does not reside within the hardware keys themselves but in the authentication steps a web browser (e.g. Google Chrome) uses to authenticate an individual.

In summary, if you are using Google Chrome, please ensure it is updated to version 67 or later and follow the additional suggestion from Yubico in their security advisory:

Security Advisory 2018-03-02 – WebUSB Bypass of U2F Phishing Protection: Yubico

Windows 10 Persistent Malware:
The security vendor BitDefender have published a 104 page report detailing a spyware (defined) which uses rootkit functionality (defined). This malware is noteworthy due to its longevity (dating back to 2012) and it’s ability to install even on modern versions of Windows e.g. Windows 10:

Six Years and Counting: Inside the Complex Zacinlo Ad Fraud Operation: BitDefenders Labs

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On a side note I am not too surprised this infection can persist on Windows 10. If a user is tricked into running malware e.g. by clicking a link or opening an attachment either of which can be contained in  a phishing (defined) email or an even more convincing spear phishing (defined) email from an organization or colleague you trust; strong defences won’t always keep you from becoming infected.

The BitDefender report can be downloaded from the above link (it does not request any personal information).

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The following news article links to 2 detailed but still easy to follow removal guides. If you are experiencing un-wanted adverts showing within websites that don’t usually show them (even though you are using an ad blocker) or are experiencing re-directs namely you wish to visit website A but are actually sent to website B, please follow these guides to remove this malware:

Rootkit-Based Adware Wreaks Havoc Among Windows 10 Users in the US: BleepingComputer: by Catalin Cimpanu
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Thank you.

Intel Lazy Floating Point Vulnerability: What you need to know

On Wednesday of last week, a further vulnerability affecting Intel CPUs (defined) was disclosed.

TL;DR: Keep your operating system up to date and you should be fine.

What makes this vulnerability noteworthy?
According to Intel’s security advisory; this is an information disclosure issue. Similar to Spectre/Meltdown the flaw is the result of a performance optimization (used when saving and restoring the current state of applications as a system switches from one application to another). A feature known as Lazy Floating Point (defined) Unit (FPU) is used to save and restore registers (defined) within the CPU used to store floating point numbers (non-integers numbers, namely decimal numbers).

The issue is that these registers may be accessed by another application on the same system. If the registers are storing for example results of performing cryptographic equations for a key you have just created or used to decrypt data, the attacker could use this data to infer what the actual key is. The same applies for any type of data the registers store; that data can be used to infer what the previous contents were via a speculative execution side channel.

This vulnerability has been rated as moderate since it is difficult to exploit via a web browser (in contrast to Spectre) and the updates will be a software update only; no microcode (defined) and/or firmware (defined) updates will be necessary. With exploitation via a web browser being difficult; this vulnerability will likely instead be exploited from the victim system (at attacker will need to have already compromised your system).

How can I protect myself from this vulnerability?
Please note; AMD CPUs are NOT affected by this vulnerability.

The following vendors have responded to this vulnerability with software updates now in progress. Separately Red Hat has completed their updates for Red Hat Linux 5, 6 and 7 (with further applicable updates still in progress).

Other vendors responses are listed below. Thank you:

Amazon Web Services

DragonFlyBSD

Intel’s Security Advisory

Linux

Microsoft Windows

OpenBSD

Xen Project

Adobe Releases Out of Band Zero Day Update

Earlier today Adobe released an out of band (un-scheduled) update for Flash Player to resolve 2x critical CVEs (defined) and 2x Important CVEs. One of these designated CVE-2018-5002 is a zero day (defined) vulnerability under active attack which originate from Microsoft Office documents with embedded Flash content. The exploits are said to trigger with little to no user interaction.

While Adobe confirmed the attacks are limited and targeted in nature, they are thought to target users in the Middle East.

This Flash Player update also adds a dialog box which prompts user when viewing an Office document if they wish to load Flash Player content.

If you use Adobe Flash Player, please install the update as soon as possible using the steps provided within Adobe’s security bulletin. Google and Microsoft will make available updates for their browsers very shortly.

Thank you.

June 2018 Update Summary

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Update: 12th June 2018:
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As scheduled Microsoft released their monthly security updates earlier today resolving 50 vulnerabilities. Further details are available within their Security Updates Guide.

In addition; there are 5 knowledge base articles detailing potential issues (all of which are pending resolutions) you may experience upon installing these updates. They are listed below for your reference:

4284819
4284835
4284826
4284867
4284880

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Adobe have not released any further updates since their out of band (un-scheduled) update last week.

As always; you can monitor the availability of security updates for most your software from the following websites (among others) or use one of the utilities presented on this 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. A useful list of all CVEs for this month is present here courtesy of BleepingComputer:
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CVE-2018-8267 | Scripting Engine Memory Corruption Vulnerability (a zero day (defined) vulnerability disclosed last month)

Microsoft Edge and Internet Explorer (similar to many other months; multiple versions of Edge and IE affected with many of the CVEs affecting the Microsoft Scripting Engine))

CVE-2018-8225 | Windows DNSAPI Remote Code Execution Vulnerability

CVE-2018-8231 | HTTP Protocol Stack Remote Code Execution Vulnerability (especially if your server hosts a Microsoft IIS installation)

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Please install the remaining updates at your earliest convenience.

As usual; 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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Original Post:
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I usually write this post on or very shortly after Update Tuesday (the second Tuesday) of the month but with an Adobe Flash zero day vulnerability (defined) already patched and given that Mozilla have also released an update this month; I felt an earlier post would be appropriate.

I’ll update this post as further updates are made available. Thank you.

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Mozilla Firefox:
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Early in June Mozilla made available security updates for Firefox and Firefox ESR (Extended Support Release):

6th June: Firefox 60.0.2 and Firefox ESR 52.8.1 and Firefox ESR 60.0.2: Resolves 1x high CVE (defined). This was a heap buffer overflow.

Further details of the security issues resolved by these updates are available in the link above. 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 resolve these security issues.

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Update: 19th June
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Apple Security Updates: Update: 19th June
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Following Apple’s release of security updates in the final days of May; they have made available further updates detailed below:

macOS High Sierra 10.13.5, Security Update 2018-003 Sierra, Security Update 2018-003 El Capitan: Resolves 32x CVEs (defined)

Safari 11.1.1: Resolves 13x CVEs

Apple iCloud for Windows (version 7.5): Resolves 16x CVEs

Apple Xcode version 9.4.1: Resolves 2x CVEs

As always; further details of these updates are available on Apple’s dedicated security updates page.

For advice on how to install updates for Apple devices, please see the steps detailed at the end of this Sophos blog post as well as this link (from my “Protecting Your PC” page).

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F-Secure Security Products:
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As mentioned in a previous post; 7-Zip has been updated to version 18.05 to resolve a vulnerability in it’s RAR packing code. The F-Secure products listed in this security advisory utilise this 7-Zip DLL (defined) and are thus being updated for the same reason.

If you use these F-Secure products, please install this critical update as soon as possible.

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Intel Lazy Floating Point Vulnerability:
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Please see my separate post for details.

Thank you.

Blog Post Shout Out: Security Advice for Summer Holidays/Travel

With the Summer holiday season approaching I wanted to provide a respectful shout out to the following security tips/articles while travelling. Even when we are out of the office and our homes; we should maintain vigilance to stay secure and safe.

Many of these tips you may already be using and many of them are simple to use but can make a real difference to ensure your time away runs smoothly and with no unwanted surprises when you return back home:

Tips such as being mindful before using a public charging station I have discussed before but these series of tips group them together for ease of use and convenience.

Some of the most important tips are:

  • Ensuring your portable devices are encrypted
  • Portable devise are carried with you or safely locked away
  • Ensure you changes passwords (from a system you own) after you have used a publically available computer
  • Enabling two factor authentication (more on this below)
  • Not making it obvious you have expensive devices with you (the tips from the US CERT below will clarify this advice)

Securing Mobile Devices During Summer Travel: US CERT
Holiday Traveling with Personal Internet-Enabled Devices: US CERT
Protecting Portable Devices: Physical Security: US CERT
International Mobile Safety Tips: US CERT
Cybersecurity for Electronic Devices: US CERT

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How to set up 2FA on eBay – go do it now!: Sophos Naked Security blog: by Maria Varmazis
Enabling 2FA for any online account is a great security measure and will be particularly useful when travelling to provide that every layer of security.
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How digital spring cleaning can protect your personal information: WMBF News: Christina Lob
Digital spring cleaning involves (among other steps) removing apps from your smartphones/tablets/computer systems that you don’t use. This enhances security since there will be less for attackers to target in terms of software vulnerabilities (reduced attack surface (defined) and the personal information these apps may store or provide access to. It will make it easier for you to maintain the device while travelling since there will fewer apps to update and the device will have more free space should you need it.

When you are back home; this spring cleaning advices further steps e.g. regularly checking your bank account and credit cards for signs of unusual or unknown transactions and reporting them as soon as possible. This is a good practice just in case any of your cards were unknowingly compromised while abroad.

For the final tips this article describes; I wanted to provide clarification:

Clearing out email inboxes is a good idea but will only enhance security if your account was compromised or you are being shoulder surfed by those around you; if you are following password and email best practices this shouldn’t happen.

Its advice on passwords could be better (this advice from Sophos is more secure) and emptying recycle bins while useful doesn’t truly delete data beyond recovery.

Thank you.

VPNFilter: Overview and removal

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Update: 20th June 2018:
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If you would prefer a video or a podcast of how to remove this malware from your router, this Sophos blog post provides links to both. The video is hosted on Facebook but a Facebook account isn’t required to view it. Sophos also provide an archive of previous videos on the same Facebook page.

Thank you.

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Update: 6th June 2018:
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The Cisco Talos team have provided an updated list of known affected routers. I have added these to the list below with “(new)” indicating a new device on the existing list. I have also updated the malware removal advice to provide easier to follow steps.

Thank you.

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Original Post:
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In late May; a strain of malware known as VPNFilter affecting routers from the vendors listed below was publically disclosed by the Cisco Talos team:

Affected vendors:
Asus RT-AC66U (new)
Asus RT-N10 (new)
Asus RT-N10E (new)
Asus RT-N10U (new)
Asus RT-N56U (new)
Asus RT-N66U (new)
D-Link DES-1210-08P (new)
D-Link DIR-300 (new)
D-Link DIR-300A (new)
D-Link DSR-250N (new)
D-Link DSR-500N (new)
D-Link DSR-1000 (new)
D-Link DSR-1000N (new)
Huawei HG8245 (new)
Linksys E1200
Linksys E2500
Linksys E3000 (new)
Linksys E3200 (new)
Linksys E4200 (new)
Linksys RV082 (new)
Linksys WRVS4400N
Mikrotik CCR1009 (new)
Mikrotik Cloud Core Router (CCR) CCR1016
Mikrotik CCR1036
Mikrotik CCR1072
Mikrotik CRS109 (new)
Mikrotik CRS112 (new)
Mikrotik CRS125 (new)
Mikrotik RB411 (new)
Mikrotik RB450 (new)
Mikrotik RB750 (new)
Mikrotik RB911 (new)
Mikrotik RB921 (new)
Mikrotik RB941 (new)
Mikrotik RB951 (new)
Mikrotik RB952 (new)
Mikrotik RB960 (new)
Mikrotik RB962 (new)
Mikrotik RB1100 (new)
Mikrotik RB1200 (new)
Mikrotik RB2011 (new)
Mikrotik RB3011 (new)
Mikrotik RB Groove (new)
Mikrotik RB Omnitik (new)
Mikrotik STX5 (new)
Netgear DG834 (new)
Netgear DGN1000 (new)
Netgear DGN2200
Netgear DGN3500 (new)
Netgear FVS318N (new)
Netgear MBRN3000 (new)
Netgear R6400
Netgear R7000
Netgear R8000
Netgear WNR1000
Netgear WNR2000
Netgear WNR2200 (new)
Netgear WNR4000 (new)
Netgear WNDR3700 (new)
Netgear WNDR4000 (new)
Netgear WNDR4300 (new)
Netgear WNDR4300-TN (new)
Netgear UTM50 (new)
QNAP TS251
QNAP TS439 Pro
Other QNAP NAS devices running QTS software
TP-Link R600VPN
TP-Link TL-WR741ND (new)
TP-Link TL-WR841N (new)
Ubiquiti NSM2 (new)
Ubiquiti PBE M5 (new)
UPVEL Unknown Models* (new)
ZTE ZXHN H108N (new)

Why should this malware be considered important?
The authors (thought to be a group funded by a nation state) of this malware are using it to hijack vulnerable routers (500,000 are known to have been compromised across 54 countries) for possible use in cyberattacks against the Ukraine. Indeed, the malware more recently began seeking out Ukrainian routers specifically. The Ukrainian Secret Service issued a security alert on this on the 23rd of May.

The malware has the ability to do so by utilising previously publically disclosed (defined) vulnerabilities to gain access and persistence (namely remaining present after the router is powered off and back on) within these routers. Last week the FBI took control of this botnet and are now working to clean up the affected devices.

The malware is very sophisticated and can persist within a router even if the router is powered off and back on (becoming the second malware to have this ability, the first being the Hide and Seek botnet). The malware is made up of 3 stages:

Stage 1: Is responsible for the persistence (mentioned above).
Stage 2: Providing the capabilities of a remote access Trojan (RAT)(defined)
Stage 3: Provides plugins for the RAT to extend it’s functionality.

The malware also has the capability to do the following:

  1. Wipe the firmware (see Aside below for a definition) of routers rendering them useless
  2. Inspect the data traffic passing through the router (with the possible intention of obtaining credentials passing over the wire to gain access to sensitive networks)
  3. Attempt to locate ICS/SCADA devices (defined) on the same network as the router by seeking out port 502 traffic, namely the Modbus protocol (defined) with the option of deploying further malware
  4. Communicate via the Tor network (definition in the Aside below).

How can I protect my devices from this malware?
The FBI are asking anyone who suspects their internet router to be infected to first reboot it (turn on and off the router). This will cause an infected device to check-in with the now under FBI control C&C (command and control, C2 (defined) server to provide them with a better overview of the numbers of infected devices.

To completely remove the malware; reset the device to factory defaults (this won’t harm a non-infected either but please ensure you have the necessary settings to hand to re-input them into the router, your internet service provider (ISP) will be able to help with this). This will remove stage 1 of the malware (stage 2 and 3 are removed by turning the router on an off).

To prevent re-infection: Cisco Talos’ team recommendations are available from this link. Moreover the US CERT provide recommendations here and here. Symantec’s recommendations are provided here (especially for Mikrotik and QNAP devices).

Further advisories from router manufacturers are as follows (their advice should supersede any other advice for your router model since they know their own devices the best):

Linksys
MiktroTik
Netgear
QNAP
TP-Link

Further recommendations from Sophos are:

  • Check with your vendor or ISP to find out how to get your router to do a firmware update.
  • Turn off remote administration unless you really need it
  • Choose strong password(s) for your router
  • Use HTTPS website where you can

A very useful and easy to follow step by step walk through of removing this malware by BleepingComputer is available from this link with useful guidance for multiple router models.

Thank you.

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References:
New VPNFilter malware targets at least 500K networking devices worldwide : Cisco Talos team
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Aside:
What is firmware?
Firmware is semi-permanent embedded software code that allows a device to carry out its function by having the low-level hardware carry out useful sequences of events.

What is The Onion Router (Tor)?
The Onion Router (Tor) is an open source (defined) project with the goal of protecting your privacy by passing your web browsing activity through a series of anonymous relies spread across the internet. These relays act like proxy servers which encrypt and randomly pass the traffic they receive from relay to relay.

This web of proxies is sometimes referred to as the Dark web (a portion of the internet only accessible using the Tor network). This makes tracing the source of the source almost impossible.
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Valve Resolves Steam Gaming Client Vulnerability

The games company Valve Corporation known primarily for their gaming client Steam have updated it to resolve a critical vulnerability which has been inadvertently present within Steam for the last 10 years.

Why should this vulnerability be considered important?
Due to the many millions of Steam users and the fact this vulnerability is remotely exploitable (since the attacker does not need to first have access to the victim system) makes this vulnerability more serious. An attacker would only have needed to send malformed UDP (defined) packets to a victim system for it to have Steam carry out instructions of their choice.

This vulnerability was a buffer overflow (defined) within one of Steam’s internal libraries (the general concept of a code library is defined here); more specifically code that dealt with UDP datagram reassembly.

How can I protect myself from this vulnerability?
In July 2017, the Steam client added Address Space Layout Randomisation (ASLR)(defined) making exploitation of the vulnerability more difficult which would then only crash the Steam client. If however an attacker combined an information leak which exposed the memory address of vulnerable library, even with ASLR enabled the result would have been the same.

Valve patched this vulnerability on April 4th. The Steam client by default updates automatically. Please open it and allow it to update to resolve this vulnerability.

Thank you.