Tag Archives: security

development, tech

Xcode on Catalina update hassles

I have a Mac running Catalina. It is almost new and I did not migrate anything from the old Mac, so should be a very clean install.

I installed Xcode 11 from the App Store. All fine.

Yesterday it wanted to update to Xcode 11.1. But the update took a long time and then failed. Try again later. I did. Same. The App Store UI gives you no clue what is not working.

I ran the Console app to check the log. Install failed “The package is attempting to install content to the system volume.”

Annoying. Suggested fix is to download the DMG. Another idea is to uninstall and then reinstall from the App Store. I like having it App Store managed so I did the latter and it worked.

Together with Gimp permission problems it looks like permission issues in Catalina are a considerable annoyance. Which is OK if security is better as a result; but that does not excuse this kind of arbitrary behaviour.

security, tech

Two Factor Authentication is great–but what if you lose your phone or have your number hijacked?

2 Comments

Account hijack is a worry for anyone. What kind of chaos could someone cause simply by taking over your email or social media account? Or how about spending money on your behalf on Amazon, eBay or other online retailers?

The obvious fraud will not be long-lasting, but there is an aftermath too. Changing passwords, getting back into accounts that have been compromised and their security information changed.

In the worst cases you might lose access to an account permanently. Organisations like Google, Microsoft, Facebook or eBay, are not easy to deal with in cases where your account is thoroughly compromised. They may not be sure whether your are the victim attempting to recover an account, or the imposter attempting to compromise an account. Even getting to speak to a human can be challenging, as they rely on automated systems, and when you do, you may not get the answer you want.

The solution is stronger security so that account hijack is less common, but security is never easy. It is a system, and like any system, any change you make can impact other parts of the system. In the old world, the most common approach had three key parts, username, password and email. The username was often the email address, so perhaps make that two key parts. Lose the password, and you can reset it by email.

Two problems with this approach. First, the password might be stolen or guessed (rather easy considering massive databases username/password combinations easily available online). And second, the email is security-critical, and email can be intercepted as it often travels the internet in plain text, for at least part of its journey. If you use Office 365, for example, your connection to Office 365 is encrypted, but an email sent to you may still be plain text until it arrives on Microsoft’s servers.

There is therefore a big trend towards 2-factor authentication (2FA): something you have as well as something you know. This is not new, and many of us have used things like little devices that display one-time pass codes that you use in addition to a password, such as the RSA SecureID key fob devices.

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Another common approach is a card and a card reader. The card readers are all the same, and you use something like a bank card, put in your PIN, and it displays a code. An imposter would need to clone your card, or steal it and know the PIN.

in the EU, everyone is becoming familiar with 2FA thanks to the revised Payment Services Directive (PSD2) which comes into effect in September 2019 and requires Strong Customer Authentication (SCA). Details of what this means in the UK are here. See chapter 20:

Under the PSRs 2017, strong customer authentication means authentication based on the use of two or more independent elements (factors) from the following categories:

• something known only to the payment service user (knowledge)

• something held only by the payment service user (possession)

• something inherent to the payment service user (inherence)

So will we see a lot more card readers and token devices? Maybe not. They offer decent security, but they are expensive, and when users lose them or they wear out or the battery goes, they have to be replaced, which means more admin and expense. Giant companies like security, but they care almost as much about keeping costs down and automating password reset and account recovery.

Instead, the favoured approach is to use your mobile phone. There are several ways to do this, of which the simplest is where you are sent a one-time code by SMS. Another is where you install an app that generates codes, just like the key fob devices, but with support for multiple accounts and no need to clutter up your pocket or bag.

These are not bad solutions – some better than others – but this is a system, remember. It used to be your email address, but now it is your phone and/or your phone number that is critical to your security. All of us need to think carefully about a couple of things:

– if our phone is lost or broken, can we still get our work done?

– if a bad guy steals our phone or hijacks the number (not that difficult in many cases, via a little social engineering), what are the consequences?

Note that the SCA regulations insist that the factors are each independent of the other, but that can be difficult to achieve. There you are with your authenticator app, your password manager, your web browser with saved usernames and passwords, your email account – all on your phone.

Personally I realised recently that I now have about a dozen authenticator accounts on a phone that is quite old and might break; I started going through them and evaluating what would happen if I lost access to the app. Unlike many apps, most authenticator apps (for example those from Google and Microsoft) do not automatically reinstall complete with account data when you get a new phone.

Here are a few observations.

First, SMS codes are relatively easy from a recovery perspective (you just need a new phone with the same number), but not good for security. Simon Thorpe at Authy has a good outline of the issues with it here and concludes:

Essentially SMS is great for finding out your Uber is arriving, or when your restaurant table is ready. But SMS was never designed to provide a secure way for you to login to your online banking account.

Yes, Authy is pitching its alternative solutions but the issues are real. So try to avoid them; though, as Thorpe notes, SMS codes are much stronger security than password alone.

Second, the authenticator app problem. Each of those accounts is actually a long code. So you can back them up by storing the code. However it is not easy to get the code unless you hack your phone, for example getting root access to an Android device.

What you can do though is to use the “manually enter code” option when setting up an account, and copy the code somewhere safe. Yes you are undermining the security, but you can then easily recover the account. Up to you.

If you use the (free) Authy app, the accounts do roam between your various devices. This must mean Authy keeps a copy on its cloud services, hopefully suitably encrypted. So it must be a bit less secure, but it is another solution.

Third, check out the recovery process for those accounts where you rely on your authenticator app or smartphone number. In Google’s case, for example, you can access backup codes – they are in the same place where you set up the authenticator account. These will get you back into your account, once for each code. I highly recommend that you do something to cover yourself against the possibility of losing your authenticator code, as Google is not easy to deal with in account recovery cases.

A password manager or an encrypted device is a good place to store backup codes, or you may have better ideas.

The important thing is this: a smartphone is an easy thing to lose, so it pays to plan ahead.

security, tech, windows

How Windows 10 Ransomware protection can cause install failures, LibreOffice for example

While researching a piece on Office applications I needed to install LibreOffice. The install failed with a message about an error creating a temporary file needed for installation.

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Fortunately I knew where to look for the answer. Windows Ransomware Protection is a feature which whitelists the applications allowed to write data to the folders likely to contain the data you care about, such as documents and pictures. The idea is that malware which wants to encrypt these folders and then demand a ransom will find it harder to do so.

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Ransomware protection can have side effects though. Operations like creating desktop shortcuts may fail because the desktop is one of the protected locations. That is just an annoyance; but in the case of LibreOffice, setup tried to write an essential file to a protected location and the install failed completely.

Solution: turn off Ransomware protection temporarily and re-run setup.

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microsoft, security, tech

Microsoft Office 365 and Google G-Suite: why multi-factor authentication is now essential

Businesses using Office 365, Google G-Suite or other hosted environments (but especially Microsoft and Google) are vulnerable to phishing attacks that steal user credentials. Here is a recent example, which sailed through Microsoft’s spam and malware filters despite its attempts to use AI and other techniques to catch them.

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If a user clicks the link and signs in, the bad guys have their credentials. What are the consequences?

– at best, a bunch of spam sent out from the user’s account, causing embarrassment and a quick password reset.

– at worst, something much more serious. Once an unauthorised party has user credentials, there are all sorts of social engineering possibilities to escalate the attack, obtain other credentials, or see what interesting data can be found in collaborative document stores and shared applications.

– another risk is to discover information about an organisation’s customers and contact them to advise of new bank details which of course direct payments to the attacker’s account.

The truth is there are many risks and it is worth every effort to prevent this happening in the first place.

However, it is hard to educate every user to the extent that you can be confident they will never click a link in an email such as the one above, or reveal their password in some other way – such as using the same one as one that has been leaked – check here to find out, for example.

Multi-factor authentication (MFA), which is now easy to set up on both Office 365 or G-Suite, helps matters by requiring users to enter a one-time code from their mobile, either via an authenticator app or a text message, before they can log in. It does not cost any extra and now is the time to set it up, if you have not already.

It seems to me that in some ways the prevalence of a few big providers in hosted email and applications has made matters easier for the hackers. They know that a phishing attack simulating, say, Office 365 support will find many potential victims.

The more positive view is that even small businesses can now easily use Enterprise-grade security, if they choose to take advantage.

I do not think MFA is perfect. It usually depends on a mobile phone, and given that possession of a user’s phone also often enables you to reset the password, there is a risk that the mobile becomes the weak link. It is well known that social engineering against mobile providers can persuade them to cancel a SIM and issue a new one to an impostor.

That said, hijacking a phone is a lot more effort than sending out a million phishing emails, and on balance enabling MFA is well worth it.

internet, security, tech

Mozilla Firefox and a DNS security dilemma

Mozilla is proposing to make DNS over HTTPS default in Firefox. The feature is called Trusted Recursive Resolver, and currently it is available but off by default:

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DNS is critical to security but not well understood by the general public. Put simply, it resolves web addresses to IP addresses, so if you type in the web address of your bank, a DNS server tells the browser where to go. DNS hijacking makes phishing attacks easier since users put the right address in their browser (or get it from a search engine) but may arrive at a site controlled by attackers. DNS is also a plain-text protocol, so DNS requests may be intercepted giving attackers a record of which sites you visit. The setting for which DNS server you use is usually automatically acquired from your current internet connection, so on a business network it is set by your network administrator, on broadband by your broadband provider, and on wifi by the wifi provider.

DNS is therefor quite vulnerable. Use wifi in a café, for example, and you are trusting the café wifi not to have allowed the DNS to be compromised. That said, there are further protections, such as SSL certificates (though you might not notice if you were redirected to a secure site that was a slightly misspelled version of your banking site, for example). There is also a standard called DNSSEC which authenticates the response from DNS servers.

Mozilla’s solution is to have the browser handle the DNS. Trusted Recursive Resolver not only uses a secure connection to the DNS server, but also provides a DNS server for you to use, operated by Cloudflare. You can replace this with other DNS servers though they need to support DNS over HTTPS. Google operates a popular DNS service on 8.8.8.8 which does support DNS over HTTPS as well as DNSSEC. 

While using a secure connection to DNS is a good thing, using a DNS server set by your web browser has pros and cons. The advantage is that it is much less likely to be compromised than a random public wifi network. The disadvantage is that you are trusting that third-party with a record of which sites you visit. It is personal data that potentially could be mined for marketing or other reasons.

On a business network, having the browser use a third-party DNS server could well cause problems. Some networks use split DNS, where an address resolves to an internal address when on the internal network, and an external address otherwise. Using a third-party DNS server would break such schemes.

Few will use this Firefox feature unless it is on by default – but that is the plan:

You can enable DNS over HTTPS in Firefox today, and we encourage you to.

We’d like to turn this on as the default for all of our users. We believe that every one of our users deserves this privacy and security, no matter if they understand DNS leaks or not.

But it’s a big change and we need to test it out first. That’s why we’re conducting a study. We’re asking half of our Firefox Nightly users to help us collect data on performance.

We’ll use the default resolver, as we do now, but we’ll also send the request to Cloudflare’s DoH resolver. Then we’ll compare the two to make sure that everything is working as we expect.

For participants in the study, the Cloudflare DNS response won’t be used yet. We’re simply checking that everything works, and then throwing away the Cloudflare response.

Personally I feel this should be opt-in rather than on by default, though it probably is a good thing for most users. The security risk from DNS hijacking is greater than the privacy risk of using Cloudflare or Google for DNS. It is worth noting too that Google DNS is already widely used so you may already be using a big US company for most of your DNS resolving, but probably without the benefit of a secure connection.

microsoft, security, tech, windows

Account options when setting up Windows 10, and Microsoft’s enforced insecurity questions

How do you sign into Windows 10? There are now four options. I ran through a Windows 10 setup using build 1803 (which was released in April this year) and noted how this has evolved. Your first decision: is this a personal or organisational PC?

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If you choose Setup for an organisation, you will be prompted to sign into Office 365, also known as Azure AD. The traditional Domain join, for on-premises Active Directory, has been shunted to a less visible option (the red encircling is mine). In larger organisations, this tends to be automated anyway.

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But this one is personal. It is a similar story. You are prompted to sign in with a Microsoft account, but there is another option, called an Offline account (again, the red circle is mine).

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This “Offline account” was in Windows 7 and earlier the only option for personal accounts. I still recommend having an administrative “offline account” set up so you can always be sure of being able to log into your PC, even without internet. Think about some of the scenarios. Someone might hack your Microsoft account, change your password, and now you cannot even log onto your PC. Unless you have an offline account.

I’ve been awkward and selected Offline account. Windows, or rather Microsoft, does not like it. Note the mind games in the screenshot below. Although I’ve made a positive selection for Offline account, the default and highlighted option now is to change my mind. I do not like this.

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Now I can set up my offline account. A screen prompts for a username, then for a password, all the time nagging that I should create an online account instead.

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I type and confirm the password; but now I get this:

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Yes, I have to create “security questions”, with no option to skip. If you try to skip, you get a “This field is required” message. Worse still, they are from a pre-selected list:

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I really hate this. These are not security questions; they are insecurity questions. Their purpose is to let me (or someone else) reset the password, forming a kind of back door into the PC. The information in the questions is semi-secret; not impossible for someone determined to discover. So Microsoft is insisting that I make my account less secure.

Of course you do not have to give honest answers. You can call your first pet yasdfWsd9gAg!!hea. But most people will be honest.

Does it matter, given that a PC account offers rather illusory security anyway? Unless you encrypt the hard drive, someone who steals the PC can reset the password by booting into Linux, or take out the disk and read it from another PC. All true; but note that Microsoft makes it rather easy to encrypt your PC with Bitlocker, in which case the security is not so illusory.

Just for completeness, here is what comes next, an ad for Cortana:

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Hey Cortana! How do I delete my security answers?

I do get why Microsoft is doing this. An online account is better in that settings can roam, you can use the Store, and you can reset the password from one PC to restore access to another. The insecurity questions could be a life-saver for someone who forgot their password and need to get back into their PC.

But such things should be optional. There is nothing odd about wanting an offline account.

Notes from the field, tech

Kaspersky encrypted connection scanning breaks ADFS login, internet-facing Dynamics CRM

I was asked to look at a case where a user could not log in to Dynamics CRM. This is an internet-facing deployment which uses ADFS (Active Directory Federation Services). The user put in valid credentials but received a 401 – unauthorized: Access is denied due to invalid credentials.

The odd thing from the user’s perspective is that everything worked fine on other PCs; but switching web browsers did not fix it.

I noticed that Kaspersky anti-virus was installed.

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Pausing Kaspersky made no difference to the error. However I came back to this after eliminating some other possible problems. I noticed that if you looked at the certificate on the ADFS site it was not from the site itself, but a Kaspersky certificate.

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The reason for this is that Kaspersky wants to inspect encrypted traffic for malware.

I understand the rationale but I dislike this behaviour. Your security software should not hide the SSL certificate of the web site you are visiting. Of course it is particularly dislikeable if it breaks stuff, as in this case. I found the setting in Kaspersky and disabled both this feature, and another which injects script into web traffic (though this proved not to be the culprit here), for the sake of Kaspersky’s “URL Advisor”).

Personally I feel that encrypted traffic should only be decrypted in the recipient application. Kaspersky’s feature is an SSL Man-in-the-Middle attack and to my mind reduces rather than increases the security of the PC. However you made the decision to trust your anti-virus vendor when you installed the software.

There are other anti-virus solutions that also do this so Kaspersky is not alone. As to why it breaks ADFS I am not sure, but regard this as a good thing since the user’s SSL connection is compromised.

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As it turns out, it isn’t essential to disable the feature entirely. You can simply set an exclusion for the ADFS site by clicking Manage exclusions.

Posted here in case others hit this issue.

intel, security, tech

Spectre and Meltdown woes continue as Intel confesses to broken updates

Intel’s Navin Shenoy says the company has asked PC vendors to stop shipping its microcode updates that fix the speculative execution vulnerabilities identified by Google’s Project Zero team:

We recommend that OEMs, cloud service providers, system manufacturers, software vendors and end users stop deployment of current versions, as they may introduce higher than expected reboots and other unpredictable system behavior.

This is a blow to industry efforts to fix this vulnerability, a process involving BIOS updates (to install the microcode) as well as operating system patches.

Intel says it has an “early version of the updated solution”. Given the length of time it takes for PC manufacturers to package and distribute BIOS updates for the many thousands of models affected, it looks like the moment at which the majority of active systems will be patched is now far in the future.

Vendors have not yet completed the rollout of the initial patch, which they are now being asked to withdraw.

The detailed microcode guidance is here. Intel also has a workaround which gives some protection while also preserving system stability:

For those concerned about system stability while we finalize the updated solutions, we are also working with our OEM partners on the option to utilize a previous version of microcode that does not display these issues, but removes the Variant 2 (Spectre) mitigations. This would be delivered via a BIOS update, and would not impact mitigations for Variant 1 (Spectre) and Variant 3 (Meltdown).

I am not sure who out there is not concerned about system stability? That said, public cloud vendors would rather almost anything than the possibility of code running in one VM getting unauthorised access to the host or to other VMs.

Right now it feels as if most of the world’s computing devices, from server to smartphone, are simply insecure. Though it should be noted that the bad guys have to get their code to run: trivial if you just need to run up a VM on a public cloud, more challenging if it is a server behind a firewall.

intel, tech

The mysterious microcode: Intel is issuing updates for all its CPUs from the last five years but you might not benefit

The Spectre and Meltdown security holes found in Intel and to a lesser extend AMD CPUs is not only one of the most serious, but also one of the most confusing tech issues that I can recall.

We are all used to the idea of patching to fix security holes, but normally that is all you need to do. Run Windows Update, or on Linux apt-get update, apt-get upgrade, and you are done.

This one is not like that. The reason is that you need to update the firmware; that is, the low-level software that drives the CPU. Intel calls this microcode.

So when Intel CEO Brian Krzanich says:

By Jan. 15, we will have issued updates for at least 90 percent of Intel CPUs introduced in the past five years, with updates for the remainder of these CPUs available by the end of January. We will then focus on issuing updates for older products as prioritized by our customers.

what he means is that Intel has issued new microcode for those CPUs, to mitigate against the newly discovered security holes, related to speculative execution (CPUs getting a performance gain by making calculations ahead of time and throwing them away if you don’t use them).

Intel’s customer are not you and I, the users, but rather the companies who purchase CPUs, which in most cases are the big PC manufacturers together with numerous device manufacturers. My Synology NAS has an Intel CPU, for example.

So if you have a PC or server from Vendor A, then when Intel has new microcode it is available to Vendor A. How it gets to your PC or server which you bought from Vendor A is another matter.

There are several ways this can happen. One is that the manufacturer can issue a BIOS update. This is the normal approach, but it does mean that you have to wait for that update, find it and apply it. Unlike Windows patches, BIOS updates do not come down via Windows update, but have to be applied via another route, normally a utility supplied by the manufacturer. There are thousands of different PC models and there is no guarantee that any specific model will receive an updated BIOS and no guarantee that all users will find and apply it even if they do. You have better chances if your PC is from a big name rather than one with a brand nobody has heard of, that you bought from a supermarket or on eBay.

Are there other ways to apply the microcode? Yes. If you are technical you might be able to hack the BIOS, but leaving that aside, some operating systems can apply new microcode on boot. Therefore VMWare was able to state:

The ESXi patches for this mitigation will include all available microcode patches at the time of release and the appropriate one will be applied automatically if the system firmware has not already done so.

Linux can do this as well. Such updates are volatile; they have to be re-applied on every boot. But there is little harm in that.

What about Windows? Unfortunately there is no supported way to do this. However there is a VMWare experimental utility that will do it:

This Fling is a Windows driver that can be used to update the microcode on a computer system’s central processor(s) (“CPU”). This type of update is most commonly performed by a system’s firmware (“BIOS”). However, if a newer BIOS cannot be obtained from a system vendor then this driver can be a potential substitute.

Check the comments – interest in this utility has jumped following the publicity around spectre/meltdown. If working exploits start circulating you can expect that interest to spike further.

This is a techie and unsupported solution though and comes with a health warning. Most users will never find it or use it.

That said, there is no inherent reason why Microsoft could not come up with a similar solution for PCs and servers for which no BIOS update is available, and even deliver it through Windows Update. If users do start to suffer widespread security problems which require Intel’s new microcode, it would not surprise me if something appears. If it does not, large numbers of PCs will remain unprotected.

security, tech

Why patching to protect against Spectre and Meltdown is challenging

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The tech world has been buzzing with news of bugs (or design flaws, take your pick) in mainly Intel CPUs, going way back, which enables malware to access memory in the computer that should be inaccessible.

How do you protect against this risk? The industry has done a poor job in communicating what users (or even system admins) should do.

A key reason why this problem is so serious is that it risks a nightmare scenario for public cloud vendors, or any hosting company. This is where software running in a virtual machine is able to access memory, and potentially introduce malware, in either the host server or other virtual machines running on the same server. The nature of public cloud is that anyone can run up a virtual machine and do what they will, so protecting against this issue is essential. The biggest providers, including AWS, Microsoft and Google, appear to have moved quickly to protect their public cloud platforms. For example:

The majority of Azure infrastructure has already been updated to address this vulnerability. Some aspects of Azure are still being updated and require a reboot of customer VMs for the security update to take effect. Many of you have received notification in recent weeks of a planned maintenance on Azure and have already rebooted your VMs to apply the fix, and no further action by you is required.

With the public disclosure of the security vulnerability today, we are accelerating the planned maintenance timing and will begin automatically rebooting the remaining impacted VMs starting at 3:30pm PST on January 3, 2018. The self-service maintenance window that was available for some customers has now ended, in order to begin this accelerated update.

Note that this fix is at the hypervisor, host level. It does not patch your VMs on Azure. So do you also need to patch your VM? Yes, you should; and your client PCs as well. For example, KB4056890 (for Windows Server 2016 and Windows 10 1607), or KB4056891 for Windows 10 1703, or KB4056892. This is where it gets complex though, for two main reasons:

1. The update will not be applied unless your antivirus vendor has set a special registry key. The reason is that the update may crash your computer if the antivirus software accesses memory is a certain way, which it may do. So you have to wait for your antivirus vendor to do this, or remove your third-party anti-virus and use the built-in Windows Defender.

2. The software patch is not complete protection. You also need to update your BIOS, if an update is available. Whether or not it is available may be uncertain. For example, I am pretty sure that I found the right update for my HP PC, based on the following clues:

– The update was released on December 20 2017

– The description of the update is “Provides improved security”

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So now is the time, if you have not done so already, to go to the support sites for your servers and PCs, or motherboard vendor if you assembled your own, see if there is a BIOS update, try to figure out it it addresses Spectre and Meltdown, and apply it.

If you cannot find an update, you are not fully protected.

It is not an easy process and realistically many PCs will never be updated, especially older ones.

What is most disappointing is the lack of clarity or alerts from vendors about the problem. I visited the HPE support site yesterday in the hope of finding up to date information on HP’s server patches,  to find only a maze of twist little link passages, all alike, none of which led to the information I sought. The only thing you can do is to trace the driver downloads for your server in the hope of finding a BIOS update.

Common sense suggests that PCs and laptops will be a bigger risk than private servers, since unlike public cloud vendors you do not allow anyone out there to run up VMs.

At this point it is hard to tell how big a problem this will be. Best practice though suggests updating all your PCs and servers immediately, as well as checking that your hosting company has done the same. In this particular case, achieving this is challenging.

PS kudos to BleepingComputer for this nice article and links; the kind of practical help that hard-pressed users and admins need.

There is also a great list of fixes and mitigations for various platforms here:

https://github.com/hannob/meltdownspectre-patches

PPS see also Microsoft’s guidance on patching servers here:

https://support.microsoft.com/en-us/help/4072698/windows-server-guidance-to-protect-against-the-speculative-execution

and PCs here:

https://support.microsoft.com/en-us/help/4073119/protect-against-speculative-execution-side-channel-vulnerabilities-in

There is a handy PowerShell script called speculationcontrol which you can install and run to check status. I was able to confirm that the HP bios update mentioned above is the right one. Just run PowerShell with admin rights and type:

install-module speculationcontrol

then type

get-speculationcontrolsettings

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Thanks to @teroalhonen on Twitter for the tip.