Category Archives: Mac

Major slowdowns headed for almost all computers

Major patches are coming, for most operating systems and devices running modern (made in the last 10 years or so) processors. Changes to Windows, Linux, macOS, and most other systems will modify the way memory is used, ameliorating critical CPU security flaws, and slowing them down significantly in the process.

There’s been a lot of secrecy around this issue, with details of the flaws — discovered several months ago — only now coming to light as O/S vendors scramble to prepare patches. The flaws (commonly referred to as Spectre and Meltdown) involve potential leaking of information, as described in a recent post on The Register:

At best, the vulnerability could be leveraged by malware and hackers to more easily exploit other security bugs.

At worst, the hole could be abused by programs and logged-in users to read the contents of the kernel’s memory. Suffice to say, this is not great. The kernel’s memory space is hidden from user processes and programs because it may contain all sorts of secrets, such as passwords, login keys, files cached from disk, and so on.

Much of this is still speculation, but the reality may be even worse, so hang onto your socks, since this is going to get ugly. It’s easy to imagine class action lawsuits arising out of the mess.

Those of you running light operating systems on older hardware may have the last laugh: while many of the world’s computers will soon be noticeably — and unavoidably — slower, yours will keep chugging along unaffected… at least until they’re used to access any of the millions of computers that power web sites and services. Major providers may have no choice but to install the updates, significantly reducing the processing power of their systems.

For computers running Windows 10, system updates are literally unavoidable, and the slowdown inevitable. The rest of us will need to decide whether to risk leaving the vulnerabilities exposed, or patch them and deal with the resulting performance hit. Exploiting the vulnerabilities is not straightforward, and it should be possible to stay safe by avoiding risky behaviour, such as indiscriminately running unknown software, visiting dubious web sites, and opening links in email. However, the full extent of the risks involved is not yet known.

Related articles

The Verge: Intel’s processors have a security bug and the fix could slow down PCs
The Verge: Microsoft issues emergency Windows update for processor security bugs
The Verge: Intel says processor bug isn’t unique to its chips and performance issues are ‘workload-dependent’
The Verge: Processor flaw exposes 20 years of devices to new attack
The Verge: How to protect your PC against the major ‘Meltdown’ CPU security flaw
Google Security Blog: Today’s CPU vulnerability: what you need to know
Bruce Schneier: Spectre and Meltdown Attacks
SANS InfoSec: Spectre and Meltdown: What You Need to Know Right Now
Techdirt: A Major Security Vulnerability Has Plagued ‘Nearly All’ Intel CPUs For Years

Update 2018Jan04: Corrected title and content to show that the problem affects all modern processors, not just those made by Intel, and that there are multiple vulnerabilities. Also added more related articles.

KRACK Wi-Fi vulnerability: what you need to know

Last week, security researchers identified a series of vulnerabilities affecting almost all Wi-Fi devices, from computers to refrigerators. The vulnerability could allow attackers to intercept wireless communications and potentially steal credentials and other sensitive information. The vulnerabilities are collectively referred to as KRACK.

The good news is that computers running Windows and Linux already have patches available. Microsoft included fixes in the October 2017 Patch Tuesday updates.

Apple says that fixes are ready for MacOS, but there’s no word on exactly when they will actually be made available.

The bad news is that mobile devices, particularly those that run Google’s Android operating system, are vulnerable, and in some cases, might stay that way indefinitely. That’s because even though Google has prepared fixes for Android, those fixes won’t get to devices made by other vendors until those vendors make them available. Some vendors are better than others at pushing updates to their devices. Worse, some devices running older O/S versions may never get updates at all, rendering them permanently insecure.

There are mitigating factors. First, because of the responsible way in which these vulnerabilities were reported, Microsoft and other major players have had time to develop fixes, while details of the vulnerabilities were kept relatively secret until recently. That means we have a head start on the bad guys this time.

Second, exploiting these vulnerabilities requires close proximity. Attacks based on these vulnerabilities can’t be executed over the Internet.

Use caution with unpatched devices

If you use a public Wi-Fi access point with an unpatched device, you’re exposed. So until patches for your device become available, you might want to disable its Wi-Fi when you’re not at home. Most devices have settings that prevent automatically connecting to Wi-Fi networks it finds in the vicinity.

IoT devices may remain vulnerable forever

‘Internet of Things’ (IoT) devices, including thermostats, cars, appliances, and basically anything that can have a computer stuffed into it, often connect to the Internet using Wi-Fi. There are no security standards for IoT devices yet, and many are extremely unlikely to ever be patched.

Recommendation: identify all of your IoT devices that have the ability to connect to the Internet. For each, make sure that you’re using a wired connection, or disable networking completely, if possible. As for devices that connect to the Internet via Wi-Fi and cannot or won’t be patched or disabled, consider taking them to the nearest landfill.

References

Infosec highlights – October 5, 2016

Cryptocurrency-mining malware known as Mal/Miner-C is targeting specific Seagate Central Network Attached Storage (NAS) devices. The malware locates the devices when they’re exposed to the Internet and installs a special file in a public folder. Unwary users try to open the file, which installs the malware on their Windows computer. Once installed, the malware uses available resources to mine the Monero cryptocurrency. There are about 7000 of these devices globally.

It’s standard practice to tell users to lock their computers when they walk away from their desks. A locked computer presents an obstacle to anyone with physical access who’s interested in poking around or stealing data. But in reality, once someone has physical access to a computer, there are ways to gain full access, even when that computer is locked. Now there’s a new technique that simplifies this task. A specially set up thumb drive is inserted in the target computer (Mac or PC), and 20 seconds later, the intruder has valid login credentials in their hands.

Two Factor Authentication (2FA or MFA) is an increasingly-common way to bolster your security when using Internet-based services and web sites. It adds a second step to the login process, which usually involves entering a special code. Many sites and services that offer 2FA send codes to your registered cell phone via SMS text messages. Unfortunately, that specific method (codes via SMS) can be co-opted by attackers who already have your password (which is increasingly likely with all the recent breaches). If you’re using SMS text for 2FA, you should look into more secure methods. Google Authenticator generates temporary, time-limited codes using an app on your smartphone. Duo Security has an app that receives special ‘push’ messages from the site you’re trying to access, and all you have to do is click a button on your cell phone to get in.

Bruce Schneier wants everyone to stop blaming the user for security problems and create systems that are more inherently secure. As things are today, the user gets most of the blame when something goes wrong. Clearly, using weak passwords, re-using passwords, and generally being vulnerable to phishing and other manipulation point to the user as the weak link. But Schneier thinks pointing at the user isn’t helpful, especially when that link is unlikely to ever change. Instead, he wants to limit the involvement of the user; to create fewer security pitfalls. He points to current efforts along those lines, including automatic security updates, and virtualization. Which are both great ideas, as long as us techie folks have a way to bypass those things.

Security and privacy roundup for January 2016

Your devices are talking about you

You already know that your web browser is tracking your activity. You are probably also aware of ‘The Internet of Things‘ – the increasing prevalence of devices that are connected to the Internet – and you recognize that any such device can also track your activities. Bruce Schneier reveals the next step in this evolution: enabling devices to share information about you. Of course, since the goal of all this surveillance is merely better-targeted advertising, most people are unlikely to care. Still, if privacy and control are important to you, this will not be welcome news.

Brian Krebs reminded us that ransomware can affect files in your cloud storage space as well as on your physical computer and network-connected devices.

A summary of software vulnerabilities over at VentureBeat shows Mac OS X topping the list for 2015. Microsoft’s security efforts seem to be paying off, as the highest-ranked version of Windows on the 2015 list is Windows 8.1 at number 10, and fewer than half the vulnerabilities as OS X.

Serious vulnerabilities were discovered in OpenSSH (a very commonly-used secure terminal client), OpenSSL (the ubiquitous security library), and Trend Micro antivirus software.

Vulnerabilities in the Linux kernel (affecting Android phones and Linux PCs) remain unpatched on many affected devices.

Google produced more patches for vulnerabilities affecting Android devices, but as always, the patches are finding their way to devices very slowly.

The very weak hashing functions MD5 and SHA1 are still being used in HTTPS encryption in some contexts.

It’s official: your smart TV can become infected with malware.

Network devices made by Juniper and Fortinet were found to contain serious vulnerabilities, including an NSA-developed back-door function and a hard-coded back-door password (more).

The free-to-use deep search tool Shodan made the news when researchers showed that it can be used to find household cameras, including baby-cams. Note that the problem here is not Shodan, which is just a useful search tool. The problem is the failure to properly secure Internet-connected devices.

There were more serious corporate security breaches in January, at Time Warner and Linode. As usual in these cases, the login credentials of subscribers were obtained by the attackers.

Amazon’s security practices were (unwillingly) tested by a customer, and found seriously deficient.

More malicious apps were found in the Google Play store. Google removed those apps, but not until they were downloaded millions of times by unsuspecting Android device users.

LG fixed a critical security hole affecting as many as ten million of its mobile devices.

Security & privacy roundup for September 2015

Android made security news in September for a lockscreen bypass hack and a ransomware app designated Android/Lockerpin.A.

Passwords in the leaked Ashley Madison user database became much easier to decrypt, once again reminding us to avoid re-using passwords.

A rogue version of the iPhone development tool XCode was found to have added malicious code to almost 500 legitimate apps. Those apps were published on the Apple App Store, and were subsequently installed by millions of iPhone and iPad users.

In other Apple-related news, a simple bypass for the Gatekeeper process, that protects Mac OS X users from malicious software, was discovered.

This month’s Flash updates prompted Brian Krebs to take another look at Adobe Shockwave. He found that even the most recent versions of Shockwave still contain very out of date versions of Flash, and strongly recommends that you remove Shockwave from all your computers.

A series of exploits against the Imgur and 8chan sites caused little damage, despite their enormous potential. The true goals of the hack are still in question, and the associated vulnerabilities on the affected sites have been fixed.

A researcher discovered several serious vulnerabilities in popular security software from Kaspersky Labs. While there’s no evidence of exploits in the wild, this is rather alarming. Anti-malware software typically has access to core system functionality, making working exploits very valuable to attackers. Kaspersky Labs acted quickly to fix the bugs, but this isn’t the first time security software has been found vulnerable, and likely won’t be the last.

A new botnet called Xor.DDoS is using compromised Linux computers to perform DDoS attacks against a variety of web sites, probably at the request of paying customers. The Linux computers hosting the botnet appear to have been compromised via weak root passwords. So far, most of the targets are in Asia. This marks a shift in platform for botnet developers, which previously focused almost exclusively on Windows.

FREAK vulnerability affects Windows, Mac, mobiles

It’s been about two weeks since the FREAK vulnerability was first reported. The flaw itself has existed for at least ten years, and we now know that it affects mobile devices, Mac OS X, and Windows.

From the related US-CERT alert:

FREAK (Factoring Attack on RSA-EXPORT Keys CVE-2015-0204) is a weakness in some implementations of SSL/TLS that may allow an attacker to decrypt secure communications between vulnerable clients and servers.

Google has released an updated version of its Android OS and Chrome browser for OS X to mitigate the vulnerability. Microsoft has released a Security Advisory that includes a workaround for supported Windows systems.

It’s now clear that this is a teaching moment for the Internet. The FREAK flaw exists because of the ridiculous (and short-lived) insistence by the US government that encryption software designated for export be made deliberately weak. The imposed restrictions ended, but the code involved in switching between strong and weak encryption remained. This intentional weakening of encryption is similar to the kind of ‘golden key’ (back door) for which intelligence organizations are currently clamouring. The lesson: Encryption Backdoors Will Always Turn Around And Bite You In The Ass. Bruce Schneier calls this a ‘security rollback‘. The Economist puts it succinctly, “…mathematics applies to just and unjust alike; a flaw that can be exploited by Western governments is vulnerable to anyone who finds it.”

Update 2015Mar19: Researchers determine that exploiting the remaining vulnerable systems is much easier than originally estimated. Thousands of iOS and Android apps are vulnerable.

Shellshock: a very bad vulnerability in a very common *nix tool

Linux and other flavours of the Unix operating system (aka *nix) run about half of the world’s web servers. Increasingly, *nix also runs on Internet-enabled hardware, including routers and modems. A huge proportion of these systems also have BASH configured as the default command interpreter (aka shell).

A serious vulnerability in BASH was recently discovered. The full extent of the danger related to this vulnerability has yet to be determined, because the bug opens up a world of possible exploits. As an example, the bug can be demonstrated by issuing a specially-crafted request to a vulnerable web server that results in that server pinging another computer.

Patches that address the vulnerability (at least partially) became available almost immediately for most Linux flavours. Apple’s OS X has yet to see a patch, but presumably that will change soon, although Apple has been oddly slow to respond to issues like this in the past.

Most average users don’t need to worry about this bug, but if you run a web server, or any server that’s accessible from the Internet, you should make sure your version of BASH is updated.

As new information emerges, I’ll post updates here.

References:

Update 2014Sep27: The first patch for BASH didn’t fix the problem completely, but another patch that does is now available for *nix systems. Still nothing from Apple for OS X. Scans show that there are thousands of vulnerable web servers on the Internet. Existing malware is being modified to take advantage of this new vulnerability. Attacks using the BASH vulnerability are already being observed. Posts from Ars Technica, Krebs on Security and SANS have additional details.

Update #2: It looks like there are more holes to be patched in BASH.

Update 2014Oct01: Apple releases a bash fix for OS X, more vulnerabilities are discovered, and either attacks based on bash vulnerabilities are increasing or attacks are subsiding, depending on who you ask.

Update 2014Oct08: Windows isn’t affected, unless you’re using Cygwin with bash. Oddly, Apple’s OS X bash patch is not available via the App Store; you have to obtain it from the main Apple downloads site. A security researcher claims to have found evidence of a new botnet that uses the Shellshock exploit.

Update 2014Oct23: Ars Technica: Fallout of Shellshock far from over

Extremely critical security flaw may affect Macs

Apple recently patched a critical vulnerability in iOS, the operating system that runs all iPhones. Now it appears that the same flaw may affect all Macs running OS X as well. So far there is no official confirmation from Apple, but security experts are warning Mac users to avoid using public networks until we know more.

Update 2014Feb24: Apple released a patch for iOS that fixes this flaw on iPhones. Meanwhile, it looks like the flaw does affect Macs (OS X). A security researcher at ImperialViolet has created a proof-of-concept test page (no longer functional). Steer your Mac web browser to that page; if you get an error message, your browser is not affected by the flaw. Vulnerable Mac browsers will see a message to that effect. Tests on my own Mac show Safari as vulnerable, while Firefox is not.

Update 2014Feb25: TechDirt has an amusing article on the surprising lack of information coming from Apple. There’s a general sense of dissatisfaction with Apple, and increasing clamour for information – any information – on how this issue affects Macs.

Update 2014Feb26: Apple has released an update for OS X that addresses this issue. OS X 10.9.2 includes several other security fixes and bug fixes.

Operating System and browser use statistics

Ars Technica recently posted an interesting summary of usage stats for operating systems and web browsers on desktop, laptop, and mobile computing platforms.

Here are a few highlights:

  • Almost half of all computers are running Windows 7, and a third still run Windows XP.
  • Internet Explorer is used on over half of all computers.
  • There is still a sizable population of computers running Internet Explorer 6.

Latest Ouch! newsletter: personal backups

This month’s Ouch! newsletter (warning: PDF) from SANS explains the importance of backups. Well worth reading, especially if you aren’t currently at least backing up your data. If you’re not sure whether you’re making backups, then I strongly recommend that you read this.

For my computers, I use a combination of techniques for backup. But the key component in my backup system is a set of tasks that run nightly, using Cobian Backup (Windows freeware) to back up data to an external hard drive.