Daily Archives: June 19, 2018

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

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Update: 24th July 2018:
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I have updated the list of vendor responses below to include further Red Hat versions and CentOS:

Red Hat Enterprise Linux 6:
https://access.redhat.com/errata/RHSA-2018:2164

Red Hat Enterprise Linux 5 and 7:
https://access.redhat.com/solutions/3485131

CentOS 6:
https://lists.centos.org/pipermail/centos-announce/2018-July/022968.html

CentOS 7:
https://lists.centos.org/pipermail/centos-announce/2018-June/022923.html

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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

Apple (currently release notes for an update to macOS to resolve the vulnerability)

DragonFlyBSD

Intel’s Security Advisory

Linux

Microsoft Windows

OpenBSD

Xen Project