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Microsoft warns of Internet Explorer flaw

TORPC
Grafter
Posts: 5,163
Registered: 08-12-2013

Microsoft warns of Internet Explorer flaw

[quote=http://www.bbc.co.uk/news/technology-27184188]Microsoft has warned consumers that a vulnerability in its Internet Explorer browser could let hackers gain access and user rights to their computer.
The flaw affects Internet Explorer (IE) versions 6 to 11 and Microsoft said it was aware of "limited, targeted attacks" to exploit it.
According to NetMarket Share, the IE versions account for more than 50% of global browser market.
Quote
'Complete control'
Microsoft said that hackers looking to exploit the flaw could host a "specially crafted website" containing content that can help them do so.
2 REPLIES
Community Veteran
Posts: 38,460
Thanks: 1,030
Fixes: 62
Registered: 15-06-2007

Re: Microsoft warns of Internet Explorer flaw

Interesting question
Will they patch it on XP users
If not - it means that they know they have a dodgy product but won't fix it for a class of users
If not - all XP users should stop using IE at once
TORPC
Grafter
Posts: 5,163
Registered: 08-12-2013

Re: Microsoft warns of Internet Explorer flaw

[quote=http://www.bbc.co.uk/news/technology-27184188]XP impact
However, the issue may be of special concern to people still using the Windows XP operating system.
That is because Microsoft ended official support for that system earlier this month.
It means there will be no more official security updates and bug fixes for XP from the firm.
Cyber security firm Symantec said it had carried out tests which confirmed that "the vulnerability crashes Internet Explorer on Windows XP".
"This will be the first zero day vulnerability that will not be patched for Windows XP users," it added.
About 30% of all desktops are thought to be still running Windows XP and analysts have previously warned that those users would be vulnerable to attacks from cyber-thieves.
Microsoft has suggested businesses and consumers still using the system should upgrade to a newer alternative.
[quote=https://technet.microsoft.com/en-us/library/security/2963983.aspx]Workarounds
Deploy the Enhanced Mitigation Experience Toolkit 4.1
The Enhanced Mitigation Experience Toolkit (EMET) helps mitigate the exploitation of this vulnerability by adding additional protection layers that make the vulnerability harder to exploit. EMET 4.1 is officially supported by Microsoft. At this time, EMET is only available in the English language. For more information, see Microsoft Knowledge Base Article 2458544.
Note EMET 3.0 does not mitigate this issue.
For more information about configuring EMET, see the EMET User's Guide:
On 32-bit systems the EMET User's Guide is located in C:\Program Files\EMET\EMET User's Guide.pdf
On 64-bit systems the EMET User's Guide is located in C:\Program Files (x86)\EMET\EMET User's Guide.pdf

Configure EMET 4.1 for Internet Explorer
EMET 4.1, in the recommended configuration, is automatically configured to help protect Internet Explorer. No additional steps are required.
Configure EMET for Internet Explorer using Group Policy
EMET can be configured using Group Policy. For information about configuring EMET using Group Policy, see the EMET User's Guide:
On 32-bit systems the EMET User's Guide is located in C:\Program Files\EMET\EMET User's Guide.pdf
On 64-bit systems the EMET User's Guide is located in C:\Program Files (x86)\EMET\EMET User's Guide.pdf
Note For more information about Group Policy, see Group Policy collection.

Set Internet and Local intranet security zone settings to "High" to block ActiveX Controls and Active Scripting in these zones
You can help protect against exploitation of this vulnerability by changing your settings for the Internet security zone to block ActiveX controls and Active Scripting. You can do this by setting your browser security to High.
To raise the browsing security level in Internet Explorer, perform the following steps:
On the Internet Explorer Tools menu, click Internet Options.
In the Internet Options dialog box, click the Security tab, and then click Internet.
Under Security level for this zone, move the slider to High. This sets the security level for all websites you visit to High.
Click Local intranet.
Under Security level for this zone, move the slider to High. This sets the security level for all websites you visit to High.
Click OK to accept the changes and return to Internet Explorer.

Note If no slider is visible, click Default Level, and then move the slider to High.
Note Setting the level to High may cause some websites to work incorrectly. If you have difficulty using a website after you change this setting, and you are sure the site is safe to use, you can add that site to your list of trusted sites. This will allow the site to work correctly even with the security setting set to High.
Impact of workaround. There are side effects to blocking ActiveX Controls and Active Scripting. Many websites that are on the Internet or on an intranet use ActiveX or Active Scripting to provide additional functionality. For example, an online e-commerce site or banking site may use ActiveX Controls to provide menus, ordering forms, or even account statements. Blocking ActiveX Controls or Active Scripting is a global setting that affects all Internet and intranet sites. If you do not want to block ActiveX Controls or Active Scripting for such sites, use the steps outlined in "Add sites that you trust to the Internet Explorer Trusted sites zone".
Add sites that you trust to the Internet Explorer Trusted sites zone
After you set Internet Explorer to block ActiveX controls and Active Scripting in the Internet zone and in the Local intranet zone, you can add sites that you trust to the Internet Explorer Trusted sites zone. This will allow you to continue to use trusted websites exactly as you do today, while helping to protect yourself from this attack on untrusted sites. We recommend that you add only sites that you trust to the Trusted sites zone.
To do this, perform the following steps:
In Internet Explorer, click Tools, click Internet Options, and then click the Security tab.
In the Select a web content zone to specify its current security settings box, click Trusted Sites, and then click Sites.
If you want to add sites that do not require an encrypted channel, click to clear the Require server verification (httpsSmiley for all sites in this zone check box.
In the Add this website to the zone box, type the URL of a site that you trust, and then click Add.
Repeat these steps for each site that you want to add to the zone.
Click OK two times to accept the changes and return to Internet Explorer.

Note Add any sites that you trust not to take malicious action on your system. Two in particular that you may want to add are *.windowsupdate.microsoft.com and *.update.microsoft.com. These are the sites that will host the update, and it requires an ActiveX Control to install the update.

Configure Internet Explorer to prompt before running Active Scripting or to disable Active Scripting in the Internet and Local intranet security zone
You can help protect against exploitation of this vulnerability by changing your settings to prompt before running Active Scripting or to disable Active Scripting in the Internet and Local intranet security zone. To do this, perform the following steps:
In Internet Explorer, click Internet Options on the Tools menu.
Click the Security tab.
Click Internet, and then click Custom Level.
Under Settings, in the Scripting section, under Active Scripting, click Prompt or Disable, and then click OK.
Click Local intranet, and then click Custom Level.
Under Settings, in the Scripting section, under Active Scripting, click Prompt or Disable, and then click OK.
Click OK two times to return to Internet Explorer.

Note Disabling Active Scripting in the Internet and Local intranet security zones may cause some websites to work incorrectly. If you have difficulty using a website after you change this setting, and you are sure the site is safe to use, you can add that site to your list of trusted sites. This will allow the site to work correctly.
Impact of workaround. There are side effects to prompting before running Active Scripting. Many websites that are on the Internet or on an intranet use Active Scripting to provide additional functionality. For example, an online e-commerce site or banking site may use Active Scripting to provide menus, ordering forms, or even account statements. Prompting before running Active Scripting is a global setting that affects all Internet and intranet sites. You will be prompted frequently when you enable this workaround. For each prompt, if you feel you trust the site that you are visiting, click Yes to run Active Scripting. If you do not want to be prompted for all these sites, use the steps outlined in "Add sites that you trust to the Internet Explorer Trusted sites zone".
Add sites that you trust to the Internet Explorer Trusted sites zone
After you set Internet Explorer to require a prompt before it runs ActiveX controls and Active Scripting in the Internet zone and in the Local intranet zone, you can add sites that you trust to the Internet Explorer Trusted sites zone. This will allow you to continue to use trusted websites exactly as you do today, while helping to protect you from this attack on untrusted sites. We recommend that you add only sites that you trust to the Trusted sites zone.
To do this, perform the following steps:
In Internet Explorer, click Tools, click Internet Options, and then click the Security tab.
In the Select a web content zone to specify its current security settings box, click Trusted Sites, and then click Sites.
If you want to add sites that do not require an encrypted channel, click to clear the Require server verification (httpsSmiley for all sites in this zone check box.
In the Add this website to the zone box, type the URL of a site that you trust, and then click Add.
Repeat these steps for each site that you want to add to the zone.
Click OK two times to accept the changes and return to Internet Explorer.

Note Add any sites that you trust not to take malicious action on your system. Two in particular that you may want to add are *.windowsupdate.microsoft.com and *.update.microsoft.com. These are the sites that will host the update, and it requires an ActiveX Control to install the update.
Unregister VGX.DLL
Click Start, click Run, type "%SystemRoot%\System32\regsvr32.exe" -u "%CommonProgramFiles%\Microsoft Shared\VGX\vgx.dll", and then click OK.
A dialog box appears to confirm that the un-registration process has succeeded. Click OK to close the dialog box.

Impact of Workaround: Applications that render VML will no longer do so once vgx.dll has been unregistered.
When a security update is available to address this issue, you should re-register vgx.dll after installing the security update. To re-register vgx.dll follow these steps:
Click Start, click Run, type "%SystemRoot%\System32\regsvr32.exe" "%CommonProgramFiles%\Microsoft Shared\VGX\vgx.dll", and then click OK.
A dialog box appears to confirm that the registration process has succeeded. Click OK to close the dialog box.

Modify the Access Control List on VGX.DLL to be more restrictive
To modify the Access Control List (ACL) on vgx.dll to be more restrictive, follow these steps:
Click Start, click Run, type "cmd" (without the quotation marks), and then click OK.
Type the following command at a command prompt make a note of the current ACL’s that are on the file (including inheritance settings) for future reference to undo this modification:
cacls "%CommonProgramFiles%\Microsoft Shared\VGX\vgx.dll"
Type the following command at a command prompt to deny the 'everyone' group access to this file:
echo y| cacls "%CommonProgramFiles%\Microsoft Shared\VGX\vgx.dll" /d everyone
Close Internet Explorer, and reopen it for the changes to take effect.
Impact of Workaround: Applications and Web sites that render VML may no longer display or function correctly.
How to undo this workaround. Before any security updates that fix this issue can be installed, this workaround must be reverted to the previous ACL configuration for vgx.dll. To revert to the previous vgx.dll ACL’s follow these steps:
Click Start, click Run, type "cmd" (without the quotation marks), and then click OK.
To revert to the previous ACL configuration for vgx.dll, type the following command and replace the ACL on vgx.dll with the ACL’s it previously had, which were recorded in step 2 of this workaround The command line to do so will vary depending on your environment:
echo y| cacls "%CommonProgramFiles%\Microsoft Shared\VGX\vgx.dll" /g original ACL’s
Close Internet Explorer, and reopen it for the changes to take effect.

Note If this workaround is applied, software that redistributes vgx.dll may fail to install. Before this software can be installed, this workaround must be reverted to the previous ACL configuration for vgx.dll.
Enable Enhanced Protected Mode For Internet Explorer 11 and Enable 64-bit Processes for Enhanced Protected Mode
Internet Explorer 11 users can help protect against exploitation of this vulnerability by changing the Advanced Security settings for Internet Explorer. You can do this by enabling Enhanced Protected Mode (EPM) settings in your browser. This security setting will protect users of Internet Explorer 11 on Windows 7 for x64-based systems, and all Windows 8 and Windows 8.1 clients.
To enable EPM in Internet Explorer, perform the following steps:
On the Internet Explorer Tools menu, click Internet Options.
In the Internet Options dialog box, click the Advanced tab, and then scroll down to the Security section of the settings list.
Ensure the checkboxes next to Enable Enhanced Protected Mode and Enable 64-bit processes for Enhanced Protected Mode (for 64-bit systems) are selected.
Click OK to accept the changes and return to Internet Explorer.
Restart your system.
Additional Suggested Actions
Protect your PC
We continue to encourage customers to follow our Protect Your Computer guidance of enabling a firewall, getting software updates, and installing antimalware software. For more information, see Microsoft Safety & Security Center.
Keep Microsoft Software Updated
Users running Microsoft software should apply the latest Microsoft security updates to help make sure that their computers are as protected as possible. If you are not sure whether your software is up to date, visit Microsoft Update, scan your computer for available updates, and install any high-priority updates that are offered to you. If you have automatic updating enabled and configured to provide updates for Microsoft products, the updates are delivered to you when they are released, but you should verify that they are installed.