|
|
|
|
| |
Credit:
The information has been provided by Microsoft Security.
The original article can be found at: http://www.microsoft.com/technet/security/Bulletin/MS06-024.mspx
|
| |
Vulnerable Systems:
* Windows Media Player for XP on Microsoft Windows XP Service Pack 1 Download the update
* Windows Media Player 9 on Microsoft Windows XP Service Pack 2 Download the update
* Windows Media Player 10 on Microsoft Windows XP Professional x64 Edition Download the update
* Windows Media Player 9 on Microsoft Windows Server 2003 Download the update
* Windows Media Player 10 on Microsoft Windows Server 2003 Service Pack 1 Download the update
* Windows Media Player 10 on Microsoft Windows Server 2003 x64 Edition Download the update
* Microsoft Windows 98, Microsoft Windows 98 Second Edition (SE), and Microsoft Windows Millennium Edition (Me) Review the FAQ section of this bulletin for details about these operating systems.
* Microsoft Windows Media Player 7.1 when installed on Windows 2000 Service Pack 4 Download the update
* Microsoft Windows Media Player 9 when installed on Windows 2000 Service Pack 4 or Windows XP Service Pack 1 Download the update
* Microsoft Windows Media Player 10 when installed on Windows XP Service Pack 1 or Windows XP Service Pack 2 Download the update
Immune Systems:
* Windows Media Player 6.4 on all Microsoft Windows operating systems
* Microsoft Windows Server 2003 for Itanium-based Systems and Microsoft Windows Server 2003 with SP1 for Itanium-based Systems
Windows Media Player PNG Vulnerability - CVE-2006-0025
A remote code execution vulnerability exists in Windows Media Player due to the way it handles the processing of PNG images. An attacker could exploit the vulnerability by constructing specially crafted Windows Media Player content that could potentially allow remote code execution if a user visits a malicious Web site or opens an email message with malicious content. An attacker who successfully exploited this vulnerability could take complete control of an affected system.
Mitigating Factors for Windows Media Player PNG Vulnerability - CVE-2006-0025:
* In a Web-based attack scenario, an attacker would have to host a Web site that contains a Web page that is used to attempt to exploit this vulnerability. An attacker would have no way to force users to visit a malicious Web site. Instead, an attacker would have to persuade users to visit the Web site, typically by getting them to click a link that takes them to the attacker's site. It could also be possible to display malicious Web content by using banner advertisements or by using other methods to deliver Web content to affected systems.
* When using Microsoft Windows 2000 Service Pack 4 with Windows Media Player 7.1 or Windows XP Service Pack 1 with Windows Media Player for XP, users are not vulnerable in a Web-based attack scenario. Users are still vulnerable if a user downloads and installs a malicious Windows Media Player skin.
* In an e-mail attack scenario, an attacker could exploit the vulnerability by sending a specially crafted .WMZ file to the user and by persuading the user to open the file.
* An attacker who successfully exploited this vulnerability could gain the same user rights as the local user. Users whose accounts are configured to have fewer user rights on the system could be less affected than users who operate with administrative user rights.
Workarounds for Windows Media Player PNG Vulnerability - CVE-2006-0025:
Microsoft has tested the following workarounds. While these workarounds will not correct the underlying vulnerability, they help block known attack vectors. When a workaround reduces functionality, it is identified in the following section.
There are several different attack vectors that Microsoft has identified for this vulnerability. Each attack vector has a different workaround.
Note The following steps require Administrator privileges. We recommend that you restart the computer after you apply this workaround. Alternatively, you can log out and log back in after you apply the workaround.
Modify the Access Control List on the DirectX Filter Graph no thread Registry Key
Modifying the Access Control List on the Filter Graph no thread registry key helps protect the affected system from attempts to exploit this vulnerability. To modify the Filter Graph no Thread Splitter registry key, follow these steps.
Note Using Registry Editor incorrectly can cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk. For information about how to edit the registry, view the "Changing Keys and Values" Help topic in Registry Editor (Regedit.exe) or view the "Add and Delete Information in the Registry" and "Edit Registry Data" Help topics in Regedt32.exe.
Note We recommend backing up the registry before you edit it.
For Windows 2000
Note Make a note of the permissions that are listed in the dialog box so that you can restore them to their original values at a later time
1. Click Start, click Run, type regedt32, and then click OK.
2. Expand HKEY_CLASSES_ROOT, expand CLSID, and then click {E436EBB8-524F-11CE-9F53-0020AF0BA770}.
3. Click Security, and then click Permissions.
4. Click to clear the Allow Inheritable Permissions from the parent to propagate to this object check box. You are prompted to click Copy, Remove, or Cancel. Click Remove, and then click OK.
5. You receive a message that states that no one will be able to access this registry key. Click Yes when you are prompted to do so.
For Windows XP Service Pack 1 or later operating systems
Note Make a note of the permissions that are listed in the dialog box so that you can restore them to their original values at a later time.
1. Click Start, click Run, type "regedit" (without the quotation marks), and then click OK.
2. Expand HKEY_CLASSES_ROOT, expand CLSID, and then click {E436EBB8-524F-11CE-9F53-0020AF0BA770}.
3. Click Edit, and then click Permissions.
4. Click Advanced.
5. Click to clear the Inherit from parent the permission entries that apply to child objects. Include these with entries explicitly defined here check box. You are prompted to click Copy, Remove, or Cancel. Click Remove, and then check OK.
6. You receive a message that states that no one will be able to access this registry key. Click Yes, and then click OK to close the Permissions for {E436EBB8-524F-11CE-9F53-0020AF0BA770} dialog box.
Note If you have backed up and removed the DirectX Filter Graph no thread registry key, you do not need to modify the Access Control List on the DirectX Filter Graph no thread registry key.
Impact of Workaround: This workaround disables image rendering and audio and video playback in any number of DirectX-enabled applications
Backup and remove the DirectX Filter Graph no thread registry key
Removing the Filter Graph no thread registry key helps protect the affected system from attempts to exploit this vulnerability. To backup and remove the Filter Graph no thread registry key, follow these steps:
Note Using Registry Editor incorrectly can cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk. For information about how to edit the registry, view the "Changing Keys and Values" Help topic in Registry Editor (Regedit.exe) or view the "Add and Delete Information in the Registry" and "Edit Registry Data" Help topics in Regedt32.exe.
Note We recommend backing up the registry before you edit it.
1. Click Start, click Run, type regedit" (without the quotation marks), and then click OK.
2. Expand HKEY_CLASSES_ROOT, expand CLSID, and then click {E436EBB8-524F-11CE-9F53-0020AF0BA770}.
3. Click File, and then click Export.
4. In the Export Registry File dialog box, type a file name in the File Name box, and then click Save.
5. Click Edit, and then click Delete to remove the registry key.
6. In the Confirm Key Delete dialog box, you receive a Are you sure you want to delete this key and all of its sub keys message. Click Yes.
Note If you have backed up and remove the DirectX Filter Graph no thread registry key, you do not need to modify the Access Control List on the DirectX Filter Graph no thread registry key.
Impact of Workaround: This workaround disables image rendering and audio and video playback in any number of DirectX-enabled applications.
Un-register Wmp.dll
Un-registering the Wmp.dll registry key helps protect the affected system from attempts to exploit this vulnerability. To modify the Wmp.dll registry key, follow these steps.
1. Click Start, click Run, type "regsvr32 -u %windir%\system32\wmp.dll" (without the quotation marks), and then click OK.
2. When a dialog box appears that confirms that the process has been successful, click OK.
3. Select the File Types tab.
Impact of Workaround: This workaround disables the Windows Media Player and applications that use the embedded Windows Media ActiveX Control.
Disassociate the WMZ file extensions
Disassociation of WMZ in Windows prevents previewing or opening WMZ files that point to malformed PNG files.
1. Launch Windows Explorer.
2. Click Tools, Folder Options and then Select the File Types tab.
3. Scroll to find the WMZ file extension and then click Delete.
Note Removing the skin file association needs to be done in addition to at least one of the workarounds listed above.
Impact of Workaround: This workaround prevents users from applying skin files to Windows Media Player by double clicking on them. Users can still apply skin files that are in their default skins directory.
FAQ for Windows Media Player PNG Vulnerability - CVE-2006-0025:
What is the scope of the vulnerability?
A remote code execution vulnerability exists in Windows Media Player due to the way it handles the processing of PNG images. An attacker could exploit the vulnerability by constructing specially crafted Windows Media Player content that could potentially allow remote code execution if a user visits a malicious Web site or clicks on a specially crafted WMZ file in an email message. An attacker who successfully exploited this vulnerability could take complete control of an affected system.
If a user is logged on with administrative user rights, an attacker who successfully exploited this vulnerability could take complete control of an affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. Users whose accounts are configured to have fewer user rights on the system could be less affected than users who operate with administrative user rights.
What causes the vulnerability?
An unchecked buffer in the PNG processing code within Windows Media Player.
What is Windows Media Player?
Windows Media Player is a feature of the Windows operating system for personal computers. It is used for playing audio and video.
What might an attacker use the vulnerability to do?
An attacker who successfully exploited this vulnerability could take complete control of the affected system.
How could an attacker exploit the vulnerability?
In a Web-based attack scenario, an attacker would have to host a Web site that contains a Web page that is used to attempt to exploit this vulnerability. An attacker would have no way to force users to visit a malicious Web site. Instead, an attacker would have to persuade them to visit the Web site, typically by getting them to click a link that takes them to the attacker's site. It could also be possible to display malicious Web content by using banner advertisements or by using other methods to deliver Web content to affected systems.
In an e-mail attack scenario, an attacker could exploit the vulnerability by sending a specially crafted file to the user and by persuading the user to open the file.
What systems are primarily at risk from the vulnerability?
Workstations and terminal servers are primarily at risk. Servers could be at more risk if users who do not have sufficient administrative permissions are given the ability to log on to servers and to run programs. However, best practices strongly discourage allowing this.
Are Windows 98, Windows 98 Second Edition, or Windows Millennium Edition critically affected by this vulnerability?
Yes. This vulnerability is critical for Windows Media Player 9 on Windows 98 Second Edition, and Windows Millennium Edition. Critical security updates for these platforms may not be available concurrently with the other security updates provided as part of this security bulletin. They will be made available as soon as possible following the release. When these security updates are available, you will be able to download them only from the Windows Update Web site. For more information about severity ratings, visit the following Web site.
What does the update do?
The update removes the vulnerability by modifying the way that the Windows Media Player validates the processing code before it passes it to the allocated buffer.
When this security bulletin was issued, had this vulnerability been publicly disclosed?
No. Microsoft received information about this vulnerability through responsible disclosure. Microsoft had not received any information to indicate that this vulnerability had been publicly disclosed when this security bulletin was originally issued.
When this security bulletin was issued, had Microsoft received any reports that this vulnerability was being exploited?
No. Microsoft had not received any information to indicate that this vulnerability had been publicly used to attack customers and had not seen any examples of proof of concept code published when this security bulletin was originally issued.
|
|
|
|
|
