Tag Archives: WinSCP

October 2019 Update Sumamry

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Update: 25th October 2019
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Apologies for the delay in updating this post due to professional commitments.

I wanted to provide details of this month’s security updates from Microsoft and Adobe. On the 8th of October, Microsoft made available their updates resolving 59 vulnerabilities more formally known CVEs (defined).

Separately Adobe made available their updates a week later:

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Adobe Acrobat and Reader: 68x Priority 2 CVEs resolved (45x critical severity, 23x Important severity)

Adobe Download Manager: Priority 3 CVE resolved (1x Important severity)

Adobe Experience Manager: Priority 2 CVEs (1x Critical CVE, 7x Important and 4x Moderate severity)

Adobe Experience Manager Forms: 1x Priority 3 CVE (1x Important severity)

As always, if you use these Adobe products, please install the necessary updates as soon as possible prioritising the Adobe Acrobat/Reader and Experience Manager updates.

====================

This month’s list of Known Issues from Microsoft is available within their monthly summary page and applies to all currently supported operating systems. All issues have workarounds at this time and none appear to be serious issues. The up to date list is available from their summary page.

As for stability, I have installed all of this month’s updates on my Windows 10 systems (Builds 18362.388 , 18362.418) most recently the new kb4522355 (for Windows 10 Version 1903 Build 18362.449) and have not experienced any issues. Indeed, this update was intended to resolve the issues e.g. among with the Start menu that caused me to advise not to install Windows 10 updates earlier this month. Obviously, please continue to backup and test your systems as you usually would before install widely rolling out these updates but in general you should be fine.

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US Computer Emergency Readiness Team (CERT) (please see the “Information on Security Updates” heading of the “Protecting Your PC” page):

https://www.us-cert.gov/

A further useful source of update related information is the Calendar of Updates.

News/announcements of updates in the categories of General SoftwareSecurity Software and Utilities are available on their website. The news/announcements are very timely and (almost always) contain useful direct download links as well as the changes/improvements made by those updates (where possible).

If you like and use it, please also consider supporting that entirely volunteer run website by donating.

====================
For this month’s Microsoft updates, I will prioritize the order of installation below:
====================
Microsoft Scripting Engine: , CVE-2019-1307 CVE-2019-1308 CVE-2019-1366

VBScript Remote Code Execution Vulnerability: CVE-2019-1238 CVE-2019-1239

Azure Stack Remote Code Execution Vulnerability : CVE-2019-1372

Remote Desktop Client Remote Code Execution Vulnerability : CVE-2019-1333

MS XML Remote Code Execution Vulnerability: CVE-2019-1060

Windows Error Reporting Manager Elevation of Privilege Vulnerability : CVE-2019-1315

Please install the remaining updates at your earliest convenience.

As per standard best practice; I would recommend backing up the data on any device for which you are installing updates to prevent data loss in the rare event that any update causes unexpected issues.

I have provided further details of updates available for other commonly used applications below.

Thank you.

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Mozilla Firefox
====================
On 22nd October Mozilla released Firefox 70 to address multiple critical vulnerabilities and to one again introduce further privacy features (see below):

Firefox 70: Resolves 1x critical CVE (defined)(but consisting of multiple vulnerabilities), 3x high CVEs, 8x moderate and 1x low CVE

Firefox ESR 68.2 (Extended Support Release): Resolves 1x critical CVE (but consisting of multiple vulnerabilities), 3x high CVEs, 5x moderate

Highlights from version 70 of Firefox include:

Details of improvements in the macOS and Windows versions of Firefox are provided in this article. The blocking of social networking tracking is discussed in another article.

Details of how to install updates for Firefox are here. If Firefox is your web browser of choice, if you have not already done so, please update it as soon as possible to benefit from the above changes.

====================
Google Chrome
====================
On October 22nd, Google released Chrome version 78.0.3904.70. This update resolves a high severity flaw that earned the researcher who reported it $20,000. The Multi-State Information Sharing and Analysis Center (MS-ISAC) stated “successful exploitation could allow an attacker to execute arbitrary code in the context of the browser, obtain sensitive information, bypass security restrictions and perform unauthorized actions, or cause denial-of-service conditions.” In total, this update contains 37 security fixes.

Google Chrome updates automatically and will apply the update the next time Chrome is closed and then re-opened. Chrome can also be updated immediately by clicking the Options button (it looks like 3 stacked small horizontal lines, sometimes called a “hamburger” button) in the upper right corner of the window and choosing “About Google Chrome” from the menu. Follow the prompt to Re-launch Chrome for the updates to take effect.

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WinSCP:
=======================
In mid October; WinSCP version 5.15.5 was released upgrading it’s embedded version of Putty (the Windows SSH client) to 0.73 (along with its SSH private key tools to the same version) resolving 2 vulnerabilities (with one other issue possibly security related). WinSCP 5.15.6 has since been released as a non-security update.

Thank you.

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Update: 8th October 2019
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Unfortunately due to professional commitments I won’t be able to update this post today with details of Adobe’s and Microsoft’s updates. I will do so as soon as possible this week.

Thanks for your understanding.

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Original Post
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On the 23rd of September Microsoft issued two out of band (unscheduled) security updates to resolve 2 zero-day (defined) vulnerabilities. The vulnerabilities affect Internet Explorer and Windows Defender.

Microsoft has drawn criticism for adding confusion to these updates since they are not available on Windows Update but must be installed manually. For Windows 10 Version 1903 this prompted the release of kb4524147 which at this time I do NOT recommend you install since it is causing some systems not to boot, not being able to print and in some cases the Start menu is crashing.

With further security updates expected from Microsoft tomorrow, please await those updates and re-assess if you should install them. I’ll updater this post tomorrow with more information on the new monthly updates.

Separately since Windows Defender updates automatically you should have received the relevant anti-malware engine update (Version: 1.1.14700.5) 48 hours after the 23rd September.

Thank you.

August 2018 Update Summary

Today Microsoft released updates to resolve 63 vulnerabilities (more formally known as CVEs (defined)).

This month also brings a new set of vulnerabilities affecting only Intel CPUs. I detail these more thoroughly in a separate post. However high level details are provided below.

Compared to previous months updates these have a smaller list of known issues (most of which have workarounds). Links to the relevant knowledge base (KB) articles are provided below:

KB4340731

KB4340733

KB4343885

KB4343892

KB4343897

KB4343900

KB4343909

====================

Adobe also released update for the following products:

Adobe Acrobat and Reader DC (priority 2, 2x CVEs)

Adobe Creative Cloud Desktop (priority 3, 1x CVE)

Adobe Experience Manager (priority 2, 3x CVEs)

Adobe Flash (priority 2, 5x CVEs)

As always if you use any of the above Adobe software, please update it as soon as possible especially in the case of Flash and Acrobat DC/Reader DC. Updates for Google Chrome will be available shortly either via a browser update or their component updater.

Please also review the out of band updates for Photoshop CC and Creative Cloud Desktop and apply them if you use these products.

You can monitor the availability of security updates for most your software from the following websites (among others) or use one of the utilities presented on this page:
—————
US Computer Emergency Readiness Team (CERT) (please see the “Information on Security Updates” heading of the “Protecting Your PC” page):

https://www.us-cert.gov/

A further useful source of update related information is the Calendar of Updates. News/announcements of updates in the categories of General SoftwareSecurity Software and Utilities are available on their website. The news/announcements are very timely and (almost always) contain useful direct download links as well as the changes/improvements made by those updates (where possible).

If you like and use it, please also consider supporting that entirely volunteer run website by donating.

====================
For this month’s Microsoft updates, I will prioritize the order of installation below:

====================

Microsoft Edge and Internet Explorer (multiple versions of Edge and IE affected)

Windows Font Library

Malicious LNK File

Microsoft Exchange

Foreshadow (L1TF) Vulnerabilities: Allow information disclosure via speculative execution; are only locally executable (rather than remotely). This vulnerability may allow one virtual machine to improperly access information from another. More details in my dedicated blog post.

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Please install the remaining updates at your earliest convenience.

As usual; I would recommend backing up the data on any device for which you are installing updates to prevent data loss in the rare event that any update causes unexpected issues. I have provided further details of updates available for other commonly used applications below.

Please find below summaries of other notable updates released this month.

Thank you.

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Nvidia Geforce Experience Software:
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In late August, Nvidia released a security advisory for their Geforce Experience software for Windows. This update resolves 3 high severity vulnerabilities (as per their CVSS base scores). The necessary updates can be obtained from here.

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VideoLAN VLC:
=======================
On the final day of August, VideoLAN made available VLC 3.0.4. This appears to be a security update for Apple macOS due to the following entries within the releases notes (however it is unclear if this overflow is exploitable by an attacker):

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Text renderer:
* Fix head buffer overflow on macOS with some fonts
=======================

For Linux and Windows this version provides fixes numerous non-security issues. Please update to version 3.0.4 to benefit from these improvements.

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Wireshark 2.4.9 and 2.6.3
=======================
v2.4.9: 3 security advisories

v2.6.3: 3 security advisories

As per standard process Linux distributions can obtain this update using the operating systems standard package manager (if the latest version is not installed automatically using the package manager you can instead compile the source code (v2.6.3) or v2.4.9). This forum thread and this forum thread may also be helpful to you with installing Wireshark on your Linux based system.

For Mac OS X and Windows, the update is available within the downloads section of the Wireshark website. In addition, a detailed FAQ for Wireshark is available here.

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WinSCP:
=======================
In late August; WinSCP version 5.13.1 was released upgrading it’s embedded OpenSSL version to 1.0.2p (which addresses 2x low severity CVEs (Link1 and Link2).

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OpenSSL
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On the 12 June and 16th April 2018; the OpenSSL Foundation issued 2 updates for OpenSSL to address 2x low severity security vulnerabilities as detailed in these security advisories (Link1 and Link2). To resolve these issues please update your OpenSSL installations to 1.1.0i (released 14th August) or 1.0.2o (released 14th August) (as appropriate).

FTP mirrors to obtain the necessary downloads are available from here.

Downloadable Tarballs (compressed/packaged code made for distribution) are available from here.

It should also be possible to use the package manager of a Linux/Unix operating system to update your OpenSSL installation as mentioned within the section titled “Installing updates for Linux distributions” on the “Protecting Your PC” page of this blog.

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VMware
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VMWare issued two security advisories for the following products during August:

Security advisory 1 (addresses 1 vulnerability of Important severity):

  • VMware Horizon 6
  • VMware Horizon 7
  • VMware Horizon Client for Windows
  • VMware Horizon View Agent
  • VMware Horizon Agents Installer (HAI)

Security advisory 2 (addresses 1 vulnerability of Critical severity):

  • VMware Workstation Pro / Player (Workstation)
  • VMware Fusion Pro, Fusion (Fusion)

If you use the above VMware products, please review the security advisories and apply the necessary updates.

March 2018 Update Summary

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Update: 5th April 2018:
====================
On the 3rd of April, Microsoft released an out of band security update for the Microsoft Malware Protection Protection Engine. Further details are available in this separate blog post.

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Separately Microsoft have since issued an update, KB4099950 to resolve the issue detailed below affecting the network adapter on Windows 7.

The new update KB4099950 must be installed before KB4088875 and KB4088878 (I assume if this is not the case that KB4088875 and KB4088878 could be uninstalled first?)

If you were experiencing any of the following issues on Windows 7 or Windows Server 2008 R2, please install the above update to resolve them:

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A new Ethernet Network Interface Card (NIC) that has default settings may replace the previous NIC and cause network issues.

Static IP address setting are lost.

These symptoms may occur on both physical computers and virtual machine that are running VMware.
====================

Thank you.

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Update: 1st April 2018:
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Microsoft have issued an out of band update for Windows 7 SP1 64 bit and Windows Server 2008 R2 SP1 64 bit to resolve resolve a regression (an un-intentional coding error resulting in a previously working software feature no longer working, alternative definition here) which introduced an additional elevation of privilege (defined) security vulnerability in the kernel (defined) of these Windows version, please see my new post for further details.

This post has also been updated with further software releases (please see below).

If you have already checked for updates and are not seeing any being offered for your Windows 7 or Windows 8.1 system, please ensure your anti-malware software is up to date. This article explains why this change was implemented by Microsoft. It also provides recommendations of how to resolve the issue of no updates being available. Windows 10 is not affected by this issue.

A known issue of a second network adapter appearing within Windows 7 has also been documented. If this occurs for you with March’s updates, this news article may be of assistance in resolving it. It is anticipated that Microsoft will resolve this issue in this month’s upcoming security updates.

Thank you.

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Original post:
====================
Last Tuesday Microsoft began distributing their scheduled security updates to resolve 74 vulnerabilities assigned to the same number of CVEs (defined). Microsoft have provided further details are provided within their Security Updates Guide.

This month there are 12 knowledge base articles detailing potential issues (some of which are pending resolutions) you may experience upon installing these updates. They are listed below for your reference:

4088787

4088782

4088776

4088786

4088779

4088876

4088879

4088875

4088878

4089344

4089229

4090450

====================

In addition to these updates; Adobe released updates for the following products:

Adobe Connect (priority 3, 2 CVEs)

Adobe Dreamweaver CC (priority 3, 1 CVE)

Flash Player v29.0.0.113 (priority 2, 2 CVEs)

Non-Microsoft browsers should update automatically e.g. Google Chrome released an update on Tuesday which includes the new Flash Player. Microsoft issued a security advisory containing details of their updates

As always; you can monitor the availability of security updates for most your software from the following websites (among others) or use one of the utilities presented on this page (since Secunia PSI will be phased out very soon):
—————
US Computer Emergency Readiness Team (CERT) (please see the “Information on Security Updates” heading of the “Protecting Your PC” page):

https://www.us-cert.gov/

A further useful source of update related information is the Calendar of Updates. News/announcements of updates in the categories of General SoftwareSecurity Software and Utilities are available on their website. The news/announcements are very timely and (almost always) contain useful direct download links as well as the changes/improvements made by those updates (where possible).

If you like and use it, please also consider supporting that entirely volunteer run website by donating.

====================
For this month’s Microsoft updates, I will prioritize the order of installation below. A useful list of all CVEs for this month is present here:

====================

Microsoft Edge and Internet Explorer (multiple versions of Edge and IE affected with many of the CVEs affecting the Microsoft Scripting Engine))

Windows Shell (CVE-2018-0883)

CredSSP (CVE-2018-0886): Please also enable the Group Policy setting to fully mitigate this issue. Further updates will be made available in subsequent months.

Microsoft Office (consisting of CVE-2018-0903 and CVE-2018-0922)

====================

Similar to last month additional updates for Spectre vulnerability were made available for Windows 10 Version 1709. Further updates are planned and will be listed in this knowledge base article.

Please install the remaining updates at your earliest convenience.

As usual; I would recommend backing up the data on any device for which you are installing updates to prevent data loss in the rare event that any update causes unexpected issues. I have provided further details of updates available for other commonly used applications below.

Thank you.

===============

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Mozilla Firefox:
=======================
This month Mozilla issued 3 sets of security updates for Firefox and Firefox ESR (Extended Support Release):

16th March: Firefox 59.0.1: Resolves 2x critical CVEs (1 of which originated from Pwn2Own 2018).

13th March: Firefox 59: Resolves 2x critical CVEs, 4x high CVEs, 7x moderate CVEs, 5x low CVEs

13th March: Firefox ESR 52.7: Resolves 2x critical, 3x high CVEs, 2x moderate CVEs

26th March: Firefox 59.0.2: Resolves 2x high severity CVEs

26th March: Firefox 52.7.3 ESR: Resolves 1x high severity CVE

Further details of the security issues resolved by these updates are available in the links above. Details of how to install updates for Firefox are here. If Firefox is your web browser of choice, if you have not already done so, please update it as soon as possible to resolve these security issues.

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Malwarebytes Anti-Malware
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Earlier this month Malwarebytes made available version 3.4.4 of their anti-malware product. While the update provides stability and performance improvements it also updates the 7-Zip DLL (defined) within it to version 18.01.

Please install this update using the steps detailed in this Malwarebytes forum post. Further details of the improvements made are available in this BleepingComputer article.

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Google Chrome:
=======================
This month Google made available 4 updates for Google Chrome; one in early March and the other in mid-March. The more recent updates resolves 45 security issues while the update from the 20th of March resolves 1 security issue.

Google Chrome updates automatically and will apply the update the next time Chrome is closed and then re-opened. Chrome can also be updated immediately by clicking the Options button (it looks like 3 stacked small horizontal lines, sometimes called a “hamburger” button) in the upper right corner of the window and choosing “About Google Chrome” from the menu. Follow the prompt to Re-launch Chrome for the updates to take effect.

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Nvidia Geforce Drivers:
=======================
This update (released on the 28th of March 2018) applies to Linux, FreeBSD, Solaris and Windows and resolves up to 8 security vulnerabilities. The steps to install the drivers are detailed here. I detailed where Nvidia list their security advisories in a previous blog post.

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OpenSSL
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On the 27th of March; the OpenSSL Foundation issued 2 updates for OpenSSL to address 1x moderate security vulnerability and 2x low severity issues as detailed in this security advisory. To resolve these issues please update your OpenSSL installations to 1.1.0h or 1.0.2o (as appropriate).

FTP mirrors to obtain the necessary downloads are available from here.

Downloadable Tarballs (compressed/packaged code made for distribution) are available from here.

It should also be possible to use the package manager of a Linux/Unix operating system to update your OpenSSL installation as mentioned within the section titled “Installing updates for Linux distributions” on the “Protecting Your PC” page of this blog.

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VMware
=======================
VMWare issued update for the following products on the 15th of March to address one important severity security vulnerability:

  • VMware Workstation Pro / Player (Workstation)
  • VMware Fusion Pro / Fusion (Fusion)

Please review this security advisory and apply the necessary updates.

=======================
Apple security updates:
=======================
In the final week of March Apple made available security updates for the following products:

=======================
Apple tvOS 11.3

Apple iOS 11.3

Apple watchOS 4.3

Apple Safari 11.1

Apple macOS High Sierra 10.13.4, Sierra and El Capitan

Apple iTunes 12.7.4 for Windows

Apple iCloud for Windows 7.4
=======================

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

Further details of these updates are available on Apple’s dedicated security updates page.

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).

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WinSCP
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In late March; WinSCP version 5.13.1 was released upgrading it’s embedded OpenSSL version to 1.0.2o (which addresses 1x moderate CVE).

December 2017 Update Summary

Earlier this month Microsoft closed out the year with a small number of security updates. They resolved 32 vulnerabilities. Further details are provided within Microsoft’s new Security Updates Guide.

Sorry for not posting this sooner; travelling for my job meant my time was much more limited.

No Known Issues were listed as occurring for this months update.

====================

Meanwhile Adobe also completed their yearly updates with a single update for Flash Player resolving a single priority 2 CVE (defined).

You can monitor the availability of security updates for most your software from the following websites (among others) or use Secunia PSI:
—————
US Computer Emergency Readiness Team (CERT) (please see the “Information on Security Updates” heading of the “Protecting Your PC” page):

https://www.us-cert.gov/

A further useful source of update related information is the Calendar of Updates. News/announcements of updates in the categories of General SoftwareSecurity Software and Utilities are available on their website. The news/announcements are very timely and (almost always) contain useful direct download links as well as the changes/improvements made by those updates (where possible).

If you like and use it, please also consider supporting that entirely volunteer run website by donating.

====================
For December Microsoft updates, I will prioritize the order of installation below:
====================
Critical severity:

Microsoft Edge and Internet Explorer (multiple versions of Edge and IE affected)

Important severity:

Windows RRAS (Routing and Remote Access) Service Remote Code Execution Vulnerability

====================

Please install the remaining updates at your earliest convenience.

As usual; I would recommend backing up the data on any device for which you are installing updates to prevent data loss in the rare event that any update causes unexpected issues.

Thank you.

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VMware AirWatch Console and other VMware Products
=======================
A security advisory for VMware AirWatch Console to address a moderate security vulnerability was made available in December. A further security advisory to address 4 important vulnerabilities within the products listed below was also published:

  • ESXi
  • vCenter Server Appliance
  • Workstation
  • Fusion

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Google Chrome:
=======================
An update for Google Chrome included 37 security fixes while a second update included 2 further fixes.

Google Chrome updates automatically and will apply the update the next time Chrome is closed and then re-opened. Chrome can also be updated immediately by clicking the Options button (it looks like 3 stacked small horizontal lines, sometimes called a “hamburger” button) in the upper right corner of the window and choosing “About Google Chrome” from the menu. Follow the prompt to Re-launch Chrome for the updates to take effect.
=======================

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Apple security updates:
=======================
During the first half of December Apple made available security updates for the following products:

=======================

Apple tvOS 11.2 and 11.2.1

Apple iOS 11.2 and 11.2.1

Apple watchOS 4.2

Apple Safari 11.0.2

Apple macOS High Sierra 10.13.2, Sierra and El Capitan

Apple iTunes 12.7.2 for Windows

AirPort Base Station Firmware Update 7.6.9 and AirPort Base Station Firmware Update 7.7.9

Apple iCloud for Windows 7.2

=======================

Please see these links from Apple for advice on backing up your iPhone and iPad. Advice for updating tvOS is available here while the steps for updating the Apple Watch are available here. Further details of these updates are available on Apple’s dedicated security updates page.

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).

=======================
Mozilla Firefox and Firefox ESR
=======================
During December Mozilla released security updates for Firefox and Firefox ESR (Extended Support Release) raising their version numbers to 57.0.2 and 52.5.2 respectively.

  • Firefox 57.0.2 resolves 1 CVE
  • Firefox ESR 52.5.2 resolves 2 CVEs.

As always full details of the security issues resolved by these updates are available in the following links:

Firefox 57.0.2
Firefox 52.5.2

Details of how to install updates for Firefox are here. If Firefox is your web browser of choice, please update it as soon as possible to resolve these security issues.

=======================
VideoLAN VLC:
=======================
In early December VideoLAN made available version 2.2.8 of VLC for Linux, Apple macOS  and Windows. It addresses 4 security vulnerabilities (3 of which were addressed in 2.2.7). If you use VLC, please update as soon as possible to address the above mentioned security vulnerabilities as well as the general software bugs that were resolved.

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WinSCP
=======================
In mid-December; WinSCP version 5.11.3 was released upgrading it’s embedded OpenSSL version to 1.0.2n (which addresses 1x moderate and 1x low severity CVEs).

The Logjam Attack: What You Need To Know

A new attack against the Diffie Hellman protocol has been made public. This weakness allows an attacker (a man in the middle (MITM)) to downgrade the key exchange protocol Diffie Hellman to 512-bit export-grade cryptography. When the TLS (Transport Layer Security) connection is secured using this few bits, it becomes vulnerable to being broken (i.e. obtaining the session key) meaning that the connection can then be eavesdropped upon.

Why is this important?
The Diffie Hellman protocol is used to secure many everyday websites using HTTPS (this makes the lock icon appear or for your browser address bar to display green). Samples of what Extended Validation certificates look like within your web browser are shown on this page. EV certificates are less common than standard single domain name certificates but these images should assist in conveying how widely used HTTPS really is. More information on TLS/SSL is available in this podcast.

Diffie Hellman is also frequently used when accessing servers remotely using SSH and within VPNs (including IPSec VPNs). VPNs are commonly used to access servers in your workplace from outside of your workplace or when using a public internet connection e.g. a coffee shop’s free WiFi.

As detailed in a technical report on this attack (see Page 3: Table 1) since a large number of devices use the same prime number (upon which the most efficient algorithm namely number field sieve for breaking a Diffie Hellman secured connection is based) this means that the time needed to break the connection is significantly reduced. Using this attack (see Page 7: Table 2), the times for breaking common Diffie Hellman secured connections are shown below:

512 bit: Linear Algebra Stage: 7.7 years; Descent Time: 10 minutes

768 bit: Linear Algebra Stage: 28,500 years; Descent Time: 2 days (within reach of academic researchers)

1024 bit: Linear Algebra Stage: 35 million years; Descent Time: 30 days (within reach of a nation state)

Source: Imperfect Forward Secrecy: How Diffie-Hellman Fails in Practice

Excellent articles on the impact of this attack and other background information can be found in this blog post and this post.

Recommended Actions:
I refer you to the section titled “What should I do?” within this page for advice on next steps.

Today I tested Mozilla Firefox (v38.0.1), Google Chrome (v43.0.2357.73, 64 bit, Beta Channel) and Internet Explorer (v11.0.19) to check if they were vulnerable to this attack.

You can check your browser by the visiting this page (also mentioned above). The result will be shown at the top of the page for you.

Both Firefox and Chrome at the time of writing were vulnerable, this is likely to be resolved very soon by both browser vendors.

IE 11 was not vulnerable to this attack (most likely since Microsoft issued MS15-055 as part of its May security updates). However since Microsoft Research is credited as a contributor along with many other computer scientists of the above mentioned report its plausible that this gave them advance notice of the issue to resolve it sooner.

If you use WinSCP, you should ensure you have the latest version installed so that you are no longer vulnerable to Logjam and other more recent OpenSSL vulnerabilities.

Update: 20th May 2015: A ComputerWorld blog post provides a table showing which browsers are currently patched against this flaw.

Update: 2nd June 2015: VideoLAN, the creators of VLC have created a ticket within their bug tracker concerning proposed changes to VLC in response to the Logjam flaw.

Update: 7th February 2016:
VideoLAN have updated their VLC media player to version 2.2.2 which addresses the Logjam security issues within their product. Further details are available in a more recent blog post.

Update: 21st May 2015: OpenSSL has published a blog post with a discussion of the Logjam attack, upcoming changes in OpenSSL in response to this attack and provides a means to check if your OpenSSL server installation is vulnerable.

Update: 31st January 2016: To further protect against the Logjam attack the OpenSSL project have now increased the length of the Diffie-Hellman handshake parameters to 1024 bits. Further details are available in this security advisory.

Update: 11th June 2015:
OpenSSL released a security advisory today to resolve 7 CVEs one of which was a workaround for the Logjam security flaw. The change made to resolve this flaw was to reject Diffie-Hellman handshake requests for parameters shorter than 768 bits. A later release of OpenSSL will extend this to 1024 bits. I would advice updating your OpenSSL installations as soon as possible to mitigate these vulnerabilities (usually by using your Linux package manager to install the applicable updates).

Update: 2nd July 2015: On the 30th of June, Apple released fixes for OS X and iOS to address the Logjam flaw within those products.

Update: 3rd July 2015: Today Mozilla released Firefox 39 and Firefox ESR (Extended Support Release) 38.1 and ESR 31.8 to address the Logjam flaw within those products.

Update: 10th July 2015: I have verified that the Opera web browser is not vulnerable to Logjam since version 30.0.1835.52 released on the 9th of June 2015.

In addition, at the time of writing (10th July 2015), Google Chrome v43.0.2357.132 (Stable, 64 bit) and Google Chrome v44.0.2403.81 (Beta, 64 bit) remain vulnerable to Logjam.

Update: 24th July 2015: At the time of writing (24th July 2015), Google Chrome v44.0.2403.107 (Stable, 64 bit) and Google Chrome v44.0.2403.89 (Beta, 64 bit) remain vulnerable to Logjam.

Update: 28th July 2015: Google Chrome v44.0.2403.125 (Stable, 64 bit) remains vulnerable to Logjam. However Google Chrome v45.0.2454.15 (Beta, 64 bit) includes a fix for Logjam. I have verified it is no longer vulnerable.

Update: 12th August 2015: Google Chrome v44.0.2403.155 (Stable, 64 bit) remains vulnerable to Logjam.

Update: 13th August 2015: OpenSSH has released v7.0 which addresses the Logjam issue within it’s implementation.

Update: 25th August 2015: VideoLAN, the creators of VLC have closed the ticket that I mentioned above (see update: 2nd June 2015) since they have resolved the Logjam issue within their code for the upcoming version 2.2.2 of VLC. A related ticket involving a regression (an unintentional introduced software bug/error) caused by the changes they made was also resolved.

Update: 3rd September 2015: Google Chrome v45.0.2454.85 (Stable, 64 bit) is no longer vulnerable to the Logjam issue since it includes the fix mentioned in the 28th of July entry (above).

I hope that the above advice assists you in securing your servers and computer systems from this new attack. I will update this article when more information concerning updates for web browsers becomes available.

Thank you.