Tag Archives: Apple Xcode

Apple Releases Xcode Security Update

In early May Apple made available a security update for their Xcode development tool bringing it to version 7.3.1. This updates resolves 1 critical severity issue assigned to 2 CVEs (defined).

This heap based (the concept of a heap is defined here) buffer overflow (defined) issue was addressed by updating Xcode’s built in Git (a convenient version control system used for software development) to version 2.7.4. This issue was caused by the mishandling of filenames. Further technical details are available here.

As always, full details of all of these updates are provided on Apple’s Security Updates page. Further release notes are available here.

If you make use of Apple Xcode, please install the appropriate update as soon as possible. For advice on how to install Apple updates, please see the resources available on the “Protecting Your PC” page of this page (in this context PC is being used in the general sense of a personal computer and does not in this case refer to a computer using a Microsoft operating system).

Thank you.

Apple Releases Security Updates To Address iMessage Vulnerability

Yesterday Apple released a very large collection of security updates that affect most of their product range to address issues among them the widely published vulnerability in the iMessage app:

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  • Apple iOS 9.3: For iPhone 4s and later, iPod touch (5th generation) and later, iPad 2 and later
  • Apple watchOS 2.2: For Apple Watch Sport, Apple Watch, Apple Watch Edition, and Apple Watch Hermes
  • Apple tvOS 9.2: For Apple TV (4th generation)
  • Apple Xcode 7.3: For OS X El Capitan v10.11 and later
  • Apple OS X El Capitan v10.11.4 and Security Update 2016-002: For OS X Mavericks v10.9.5, OS X Yosemite v10.10.5, and OS X El Capitan v10.11 to v10.11.3
  • Apple Safari 9.1: For OS X Mavericks v10.9.5, OS X Yosemite v10.10.5, OS X El Capitan v10.11 to v10.11.3
  • Apple OS X Sever 5.1: For OS X Yosemite v10.10.5 and later

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As always, comprehensive details of all of these updates are provided on Apple’s Security Updates page.

Without question the most important update is for iOS bringing it to version 9.3. This issue is also present in watchOS and OS X. These updates resolve the cryptographic flaw in Apple’s iMessage app as reported by Matthew Green and his team of research students known as CVE-2016-1788 (defined). I will provide more detail on this vulnerability below.
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Noteworthy fixes included are as follows:

Apple iOS 9.3: Resolves 38 CVEs and includes fixes for AppleUSBNetworking, FontParser, HTTPProtocol, iOS kernel (defined), libxml2, Security, TrueTypeScaler, WebKit (and associated components and Wi-Fi (among others).

Apple watchOS 2.2: Resolves 34 CVEs and includes fixes for DiskImages, FontParser, HTTPProtocol, IOHIDFamily, watchOS kernel, libxml2, Messages, Security, syslog, TrueTypeScaler, WebKit and Wi-Fi.

Apple tvOS 9.2: Addresses 23 CVEs, the most severe present in the following components: DiskImages, FontParser, HTTPProtocol, IOHIDFamily, watchOS kernel, libxml2, Messages, Security, syslog, TrueTypeScaler, WebKit and Wi-Fi.

Apple Xcode 7.3: Resolves 2 critical CVEs.

Apple OS X El Capitan v10.11.4 and Security Update 2016-002: Resolves 59 CVEs the most severe being present in the following: apache_mod_php, AppleRAID (defined), AppleUSBNetworking, Bluetooth, Carbon, dyld, FontParser, HTTPProtocol, Intel Graphics Driver (defined), IOGraphics, IOUSBFamily, OS X kernel, libxml2, Messages, Nvidia Graphics Drivers, OpenSSH, OpenSSL, Python, QuickTime, Ruby, Security, Tcl, TrueTypeScaler, Wi-Fi.

Update: 30th March 2016:
The update for OS X 10.11 (El Capitan) also addresses a vulnerability in the System Integrity Protection (SIP) present in the most recent version of the OS. This vulnerability was assigned the following CVE: CVE-2016-1757 Further discussion of this vulnerability is available here.

Apple Safari 9.1: Resolves 12 CVEs the most critical being present in the libxml2 and WebKit (the renderer of Safari).

Apple OS X Server 5.1: Addresses 4 CVEs the most severe of which could allow information disclosure.

An alternative summary of these updates is available within Intego’s blog post.

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Why Should The Critical Cryptographic Flaw Resolved in the Updated Messages App be Considered Important?
From the information that has been made available on this attack it appears to be a side-channel attack; namely one where real world data is gathered in how the cryptosystem works. This is then used to attack it. If an attacker were to access Apple’s servers without being detected and obtained cipher texts(encrypted messages sent using iMessage) they could given sufficient time decrypt the attachments of the messages which can be photos or other files providing that either the sender or receiver of that encrypted message is online.

The tests to decrypt the attachments are done by sending 2^18 (invisible) encrypted messages to the target device. For each response, an attacker can tell if they “guessed” the encryption of that segment of the attachment correctly. This process must be repeated over and over until the entire attachment has been decrypted. It took the researchers over 70 hours to complete a proof of concept attack using un-optimized code but they estimate with optimized code only a fraction of 1 day would be needed.

A more complete technical description is available in Matthew Green’s blog post.

How Can I Protect Myself From This Issue?
As mentioned below if you own any devices that have Apple iOS, watchOS, tvOS or OS X or you know someone that does, advise them to use the links below to install the most recent security updates.
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If you use any of the above software, please install the appropriate updates as soon as possible.

As a routine precaution I would recommend backing up the data on any device for which you are installing updates (preferably to an external storage device that can easily be accessed by you) in order to prevent data loss in the rare event that any update causes unexpected issues.

Please see these links from Apple for advice on backing up your iPhone and iPad. Advice for updating tvOS is available here.

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).

Thank you.

Apple Releases Security Updates December 2015

On the 8th and 11th of December Apple released numerous security updates for the following products:

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  • Apple iOS 9.2: For iPhone 4s and later, iPod touch (5th generation) and later, iPad 2 and later
  • Apple tvOS 9.1: For Apple TV (4th generation)
  • Apple OS X: For OS X Mavericks v10.9.5, OS X Yosemite v10.10.5 (2 updates), OS X El Capitan v10.11 and v10.11.1
  • Apple watchOS v2.1: For Apple Watch Sport, Apple Watch, Apple Watch Edition, and Apple Watch Hermes
  • Apple Safari 9.0.2: For OS X Mavericks v10.9.5, OS X Yosemite v10.10.5, OS X El Capitan v10.11 and v10.11.1
  • Apple Xcode 7.2: For OS X Yosemite v10.10.5 or later
  • Apple iTunes 12.3.2: For Windows 7 and later

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Comprehensive details of all of these updates are provided on Apple’s Security Updates page.

If you wish to prioritize these updates I would suggest beginning with installing the updates for iOS, OS X, watchOS and tvOS as well as Safari due to the number and severity of the issues they address (the most serious resulting in an attacker having the ability to run code of their choice (remote code execution) with kernel or system level privileges).

Noteworthy fixes included are as follows:

Apple iOS 9.2: Resolves 51 CVEs (defined) and includes fixes for AppleMobileFileIntegrity, CoreGraphics, GPUTools Framework, ImageIO, iOS Kernel, libc, MobileStorageMounter, iOS Safari and WebKit (among others)

Apple OS X and Security Update 2015-006 Yosemite: Resolves 55 CVEs which includes fixes for apache_mod_php, AppSandbox, Bluetooth, , CoreGraphics, CoreMedia Playback, EFI, Intel Graphics Driver, OS X kernel, libc, OpenGL, OpenSSH and System Integrity Protection (among others).

Apple tvOS 9.1: Resolves 45 CVEs including security issues within AppleMobileFileIntegrity, CoreGraphics, CoreMedia Playback, ImageIO, tvOS kernel, libc, MobileStorageMounter, OpenGL and WebKit (among others).

Apple watchOS 2.1: Resolves 30 CVEs within components such as AppSandbox, CoreGraphics, CoreMedia Playback, FontParser, GasGauge, ImageIO, watchOS kernel, libc, OpenGL and Sandbox (among others).

Apple Safari 9.0.2: Resolves 12 CVEs all within WebKit (the renderer of Safari).

Apple Xcode 7.2: Resolves 4 CVEs. The most serious of which were present within the otools component of Xcode.

Apple iTunes 12.3.2: Resolves 12 CVEs: all within WebKit. This updates applies to the Windows version of iTunes only.
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If you use any of the above software, please install the appropriate updates as soon as possible.

As a routine precaution I would recommend backing up the data on any device for which you are installing updates (preferably to an external storage device that can easily be accessed by you) in order to prevent data loss in the rare event that any update causes unexpected issues.

Please see these links from Apple for advice on backing up your iPhone and iPad.

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).

Thank you.

Apple Releases Security Updates October 2015

On Wednesday of last week Apple made available a large collection of security updates to resolve vulnerabilities across it’s product range:

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  • Apple OS X Server 5.0.15: For OS X Yosemite v10.10.5, OS X El Capitan v10.11.1 or later).
  • Apple Xcode 7.1: For OS X Yosemite v10.10.5, OS X El Capitan v10.11.1 or later.
  • Mac EFI: For OS X Mavericks v10.9.5.
  • Apple iTunes: For Windows 7 and later (while this was also available for Apple systems it does not appear to contain security related changes i.e. Apple devices may not be vulnerable to those vulnerabilities).
  • OS X El Capitan 10.11.1 and Security Update 2015-007: For OS X Mavericks v10.9.5, OS X Yosemite v10.10.5, and OS X El Capitan v10.11.
  • Apple Safari 9.0.1: For OS X Mavericks v10.9.5, OS X Yosemite v10.10.5, and OS X El Capitan v10.11.
  • Apple watchOS v2.0.1: For Apple Watch Sport, Apple Watch, Apple Watch Edition, and Apple Watch Hermes.
  • Apple iOS 9.1: For iPhone 4s and later, iPod touch (5th generation) and later, iPad 2 and later.

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Full details on all updates are available on Apple’s Security Updates page. If you wish to prioritize these updates I would suggest beginning with installing the updates for OS X, iOS, watchOS, Safari and OS X Server due to the number and severity of the vulnerabilities that they address.

Noteworthy fixes included are as follows:

OS X Server 5.0.15: Resolves 3 CVEs (defined) with potentially high severity (includes 2 CVEs in ISC BIND).

Apple Xcode 7.1: Addresses a Swift type conversion issues (1 CVE).

Mac EFI Security Update 2015-002: Addresses 1 potentially high severity CVE

Apple iTunes 12.3.1: Addresses 12 critical CVEs.

Apple OS X El Capitan 10.11.1 and Security Update 2015-007: Addresses 60 CVEs and includes fixes for apache_mod_php, CoreText, EFI, FontParser, Grand Central Dispatch, Graphics Drivers, OS X kernel, OpenGL and OpenSSH (among others).

Apple Safari 9.0.1: Addresses 9 critical CVEs in WebKit (the renderer of Safari).

Apple watchOS v2.0.1: Resolves 14 CVEs which includes fixes for Apple Pay, CoreGraphics, FontParser and Grand Central Dispatch (among others).

Apple iOS 9.1: Includes fixes for 49 CVEs; notable fixes of which are CoreGraphics, CoreText, FontParser, Grand Central Dispatch, Graphics Driver, iOS kernel, OpenGL and WebKit (among others).

If you use any of the above software, please install the appropriate updates as soon as possible.
As a routine precaution I would recommend backing up the data on any device for which you are installing updates (preferably to an external storage device that can easily be accessed by you) in order to prevent data loss in the rare event that any update causes unexpected issues.

Please see these links from Apple for advice on backing up your iPhone and iPad especially since the iOS upgrade is a significant one.

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).

Thank you.

Blog Post Shout Out September 2015

Update: 24th November 2015:
Since this blog post was written FireEye have continued to monitor the command and control servers (defined) of XcodeGhost to determine where devices are located that are connecting to these servers and to determine if this malware still poses a threat. They have also found an updated version of XcodeGhost that they have named “XcodeGhost S”.

FireEye have worked with Apple to remove an app from the App Store that was found to be infected with this new variant of the malware.

In addition, an app development firm Possible Mobile has detailed in a blog post how their newly updated app that was built with a verifiably legitimate version of Apple Xcode was being rejected by Apple since their app contained the XcodeGhost malware. It was eventually found that while the code written by Possible Mobile was clean, the third party libraries and frameworks used to provide essential functionality within their app were found to contain the infected code. How Possible Mobile resolved this issue, is detailed in their blog post.

How Can I Protect Myself From This Issue?
In addition to the guidance provided within the blog posts linked to below I would recommend the following:

  1. If you are an app developer and are submitting apps to the Apple App Store it may be worthwhile to follow the steps within Possible Mobile’s blog post concerning validating your copy of Apple Xcode and checking any third party libraries for infection.
  2. As detailed in FireEye’s blog post, for all of the apps installed on your Apple devices, ensure they are the latest versions. This Apple Support article explains how to enable automatic app updates. This is important since later versions of apps should not contain this malware. FireEye discovered large numbers of users (exact figures are provided in this FireEye blog post) still using older versions of their app which still contained the infected code).
  3. If you were using one of the apps removed by Apple from the App Store, uninstall those apps and switch to similar/alternative apps available within the App Store.
  4. Ensure that your Apple device is using the most recent version of iOS that is available for your device. If your device is too old to support iOS 9, this blog post may help to explain your options. Updating to most recent iOS will ensure that you are not affected by the original version of XcodeGhost. Moreover, iOS 9 and iOS 9.1 contain many fixes for other security vulnerabilities.

Thank you.

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Original Post:
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In recent days there has been detailed coverage of a new technique used to tamper with legitimate Apple iOS apps by adding extra code to those apps when they were being compiled (converted from human written source code into a form that a computer can use). That additional code called XcodeGhost was also found to contain a vulnerability that could allow remote access to the infected apps using a man-in-the-middle (MITM) (defined) attack as discussed in the ThreatPost article mentioned below.

In addition, a new technique used by malware authors to install a rootkit (see Aside below for a definition) on a user’s Android smartphone by having them download a popular app has also been discovered.

In order to provide advice and further information on how to protect yourself from these threats I wanted to respectfully give a shout out for the following new articles and blog posts:

I hope that you find these useful in further securing your Apple iOS or Google Android based smartphone from malware.

Thank you.

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Aside:
What is a rootkit?
To provide a comprehensive definition of a rootkit I have chosen to quote from 2 well-known texts on the subject written by Reverend Bill Blunden in his book “The Rootkit Arsenal” (1st edition, Wordware Publishing 2009) and “Rootkits: Subverting the Windows Kernel” by Greg Hoglund and James Butler (Addison-Wesley, 2005). My thanks to them for providing excellent sources of information on this topic:

“A rootkit is a collection of tools (e.g. binaries, scripts, configuration files) that allow intruders to conceal their activity on a computer so that they can covertly monitor and control the system for an extended period of time by maintaining access to the root (defined) account.

While the above definition mentions a computer it still applies equally to smartphones since they run sophisticated operating systems, in this case Google Android.
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Apple Releases Security Updates for OS X Server, iOS, iTunes and Xcode

Yesterday Apple made available a large collection of security updates for the following list of products:

  • Apple OS X Server: OS X Yosemite (10.10.5 or later)
  • Apple iTunes (for Windows 7 and later)
  • Apple Xcode 7.0 (for OS X Yosemite v10.10.4 or later)
  • Apple iOS 9: iPhone 4s and later, iPod touch (5th generation) and later, iPad 2 and later

Full details on all updates are available on Apple’s Security Updates page. I would suggest prioritizing the installation of the updates for iOS, OS X Server and iTunes since they resolve the largest number of CVEs (defined) and address serious security issues in OS X Server.

Noteworthy fixes included are as follows:
Apple Xcode 7.0: Includes fixes for 10 CVEs (which includes 4 issues in OpenSSL, 2 in subversion (svn) and 1 in the API of the Apache configuration).

Apple iTunes 12.3: Includes fixes for 66 CVEs (includes 7 critical issues with CoreText, 2 issues in ICU and 55 critical issues in WebKit (the renderer within iTunes)).

OS X Server: Addresses 20 CVEs (which includes critical issues resolved within PostgreSQL).

Apple iOS 9: Includes fixes for Apple Pay, CoreCrypto, CoreText, iOS kernel, libc, libpthread, Safari, OpenSSL, Siri and WebKit (among others) (101 CVEs addressed in total with a further 5 issues not assigned a CVE at this time).

If you use any of the above software, please install the appropriate updates as soon as possible. As a routine precaution I would recommend backing up the data on any device for which you are installing updates (preferably to an external storage device that can easily be accessed by you) in order to prevent data loss in the rare event that any update causes unexpected issues.

Please see these links from Apple for advice on backing up your iPhone and iPad especially since the iOS upgrade is a significant one.

Further details of the features/improvements incorporated into iOS 9 are located here, here and here.

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).

Thank you.