Daily Archives: May 23, 2018

Blog Post Shout Out: Google Chrome Cleanup and GDPR

Google have made available a clean-up tool within Google Chrome to remove threats such as adware, browser hijackers, fake system optimizers, & tracking software which may impacting your browsing experience.

This tool from ESET appears to be a revised version of the tool I discussed over 3 years ago. This blog post from Lawrence Abrams of Bleeping Computer provides more details of how to use it and what data it collects (and sends to Google who retain it for 14 days). If you are experiencing issues with Google Chrome, this tool is a good place to start your troubleshooting. If necessary a full reset can later be performed.

====================
Separately with the European General Data Protection Regulation (GDPR) (written by Dr. Jessica Barker) due to come into effect on the 25th of May; you may be receiving emails from every online service or account that you have advising of their approach to the new regulation.

Most of the emails do not ask you to take any action however some will request you to review the information they have on file/record and update it if necessary. My advice for these emails is treat them as you would any email you receive regarding an online account, with caution.

If for example you receive an email purporting to be from PayPal but you don’t have a PayPal account, delete it! For the emails you do receive; if you suspect they are fraudulent, as per past advice from SANS call the company yourself and verify they are sending such emails and what if any actions they wish you to take? Be very careful if you do click on the links and think before you provide any personal information (in almost all cases you won’t have to enter anything).

====================
I hope the above blog posts which I have provided a respectful shout out for provide a useful resolution if you are experiencing issues with Google Chrome and guidance on how to approach the large volume of email you are likely receiving.

====================
Update: 24th May 2018
====================
I received a call yesterday from one online account I hold stating they sent me an email yesterday relating to GDPR and asking me to update my preferences. While it was a genuine call (I did receive the email that very morning); I had not yet acted on it. The person even offered to call me back today to check I had updated my preferences. I explained I would update them and a call back would not be necessary.

This very much is the exception, no other online account have called me. As always; be cautious accepting calls and don’t provide any personal information to someone you do not know; they may not be who they claim to be.

Thank you.

Vendors Respond to Spectre NG Vulnerabilities

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

Red Hat Enterprise Linux 7:
https://access.redhat.com/errata/RHSA-2018:1629

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

CentOS 7:
https://lists.centos.org/pipermail/centos-announce/2018-May/022843.html
====================

====================
Update: 19th June 2018
====================
Last Wednesday, the security news and troubleshooting website BleepingComputer published a table detailing the complete list of updates required to mitigate the Meltdown, Spectre and SpectreNG (also known as Spectre variant 4) vulnerabilities for all recent versions of Windows. This is very useful because I realise my previous blog post on Meltdown and Spectre was at times hard to follow (it has a lot of info within it).

As of Tuesday, 12th June Microsoft have released updates to address SpectreNG. While you can install these updates Microsoft have advised their security protections will not be enabled unless you choose to do so. This is due to the lower risk of SpectreNG and also given that enabling the security enhancements of these updates can lead to a performance penalty of up to 8% (as I detailed below).

Microsoft provide step by step advice and guidance if you wish to enable these updates within this security advisory. It is likely other OS vendors will take a similar approach e.g. Red Hat may also choose to distribute these updates but not enable them so as to work around the performance penalty.

For more information on the semi-related Intel Lazy Floating point vulnerability, please see my separate post.

Thank you.

====================
Original Post
====================
On Monday more details of these vulnerabilities were made available by affected vendors among them Red Hat, Google, Intel, IBM and Microsoft. There are two new vulnerabilities named:

Rogue System Register Read (Spectre Variant 3a) (CVE-2018-3640)

Speculative Store Bypass (SSB) (Spectre Variant 4) (CVE-2018-3639)

Why should these vulnerabilities be considered important?

Rogue System Register Read cannot be leveraged by an external attacker; they must instead log onto a vulnerable system and carry out further steps to exploit it. Once exploited the attacker may be able to obtain sensitive information by reading system parameters via side-channel analysis.

For Windows; successful exploitation of this vulnerability will bypass Kernel Address Space Layout Randomization (KASLR) protections. I have talked about ASLR (defined) before but provides this link more detail on kernel ASLR.

Google Project Zero’s Jann Horn and Microsoft’s Ken Johnson first reported Speculative Store Bypass. It can possibly be used by attacker externally (from the internet). I use the term “possibly” since the mitigations added to web browsers following Spectre variant 2 earlier this year will make it more difficult for an attacker to do so. Indeed, Intel rates the risk as “moderate.” This is a more serious vulnerability which may allow an attacker access to read privileged memory areas. An example would be a script running in one browser tab being able to read data from another browser tab.

Red Hat have made available a video more clearly explaining the Speculative Store Bypass (SSB) vulnerability.

How can I protect myself from these vulnerabilities?
At this time microcode updates are being developed by Red Hat, AMD, ARM, Intel, IBM and Microsoft. The affected products from many popular vendors are available from the following links. These vulnerabilities will not be addressed via software fixes but hardware fixes instead.

It is recommended to follow the best practice advice for these vulnerabilities as per the US-CERT namely:

1. Please refer to and monitor the links below for the updates from affected vendors.
2. Test these updates before deploying them widely
3. Ensure the performance impact (anticipated to be between 2 – 8%) is acceptable for the systems you manage/use.

These updates will ship with the mitigations disabled and if appropriate/acceptable for an affected system; the protection (along with its performance impact) can be enabled.

These updates are scheduled to be made available before the end of May. Cloud vendors (e.g. Amazon AWS, Microsoft Azure etc.) will also update their systems once the performance impact is determined and if deemed acceptable.

Thank you.

====================
AMD:
https://www.amd.com/en/corporate/security-updates

ARM:
https://developer.arm.com/support/arm-security-updates/speculative-processor-vulnerability

Cisco:
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180521-cpusidechannel

IBM:
https://www.ibm.com/blogs/psirt/potential-impact-processors-power-family/

Intel:
https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00115.html

Microsoft (full impact yet to be determined):
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/ADV180012

https://portal.msrc.microsoft.com/en-us/security-guidance/advisory/ADV180013

Red Hat:
https://access.redhat.com/security/cve/cve-2018-3639

Oracle:
https://blogs.oracle.com/oraclesecurity/processor-vulnerabilities-cve-2018-3640-and-cve-2018-3639

SUSE:
https://www.suse.com/de-de/support/kb/doc/?id=7022937

Ubuntu:
https://wiki.ubuntu.com/SecurityTeam/KnowledgeBase/Variant4

VMware ESXI, Fusion/Fusion Pro, Workstation/Workstation Pro and vCenter Server:
https://www.vmware.com/security/advisories/VMSA-2018-0012.html

https://kb.vmware.com/s/article/54951

https://kb.vmware.com/s/article/55111
====================