Showing posts with label CVE-2017-5754. Show all posts
Showing posts with label CVE-2017-5754. Show all posts

Wednesday, August 14, 2019

KB4056890: Windows 10 Version 1607 and Windows Server 2016 January 2018 Update Meltdown Sceptre

Description
The remote Windows host is missing security update 4056890 or 4057142. It is, therefore, affected by multiple vulnerabilities :

- An vulnerability exists within microprocessors utilizing speculative execution and indirect branch prediction, which may allow an attacker with local user access to disclose information via a side-channel analysis.
(CVE-2017-5715, CVE-2017-5753, CVE-2017-5754)

- An elevation of privilege vulnerability exists when the Windows kernel fails to properly handle objects in memory. An attacker who successfully exploited this vulnerability could run arbitrary code in kernel mode.
An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. (CVE-2018-0744)

- A remote code execution vulnerability exists in the way that the scripting engine handles objects in memory in Microsoft Edge. The vulnerability could corrupt memory in such a way that an attacker could execute arbitrary code in the context of the current user. An attacker who successfully exploited the vulnerability could gain the same user rights as the current user. (CVE-2018-0758, CVE-2018-0769, CVE-2018-0770, CVE-2018-0776, CVE-2018-0777, CVE-2018-0781)

- An information disclosure vulnerability exists in the Windows kernel that could allow an attacker to retrieve information that could lead to a Kernel Address Space Layout Randomization (ASLR) bypass. An attacker who successfully exploited the vulnerability could retrieve the memory address of a kernel object. (CVE-2018-0746, CVE-2018-0747)

- An elevation of privilege vulnerability exists when Microsoft Edge does not properly enforce cross-domain policies, which could allow an attacker to access information from one domain and inject it into another domain. (CVE-2018-0803)

- An information disclosure vulnerability exists in Windows Adobe Type Manager Font Driver (ATMFD.dll) when it fails to properly handle objects in memory. An attacker who successfully exploited this vulnerability could potentially read data that was not intended to be disclosed. Note that this vulnerability would not allow an attacker to execute code or to elevate their user rights directly, but it could be used to obtain information that could be used to try to further compromise the affected system. (CVE-2018-0754)

- A remote code execution vulnerability exists in the way the scripting engine handles objects in memory in Microsoft browsers. The vulnerability could corrupt memory in such a way that an attacker could execute arbitrary code in the context of the current user. An attacker who successfully exploited the vulnerability could gain the same user rights as the current user.
(CVE-2018-0762, CVE-2018-0772)

- An information disclosure vulnerability exists when Microsoft Edge PDF Reader improperly handles objects in memory. An attacker who successfully exploited the vulnerability could obtain information to further compromise the users system. (CVE-2018-0766)

- An elevation of privilege vulnerability exists in the way that the Windows Kernel API enforces permissions. An attacker who successfully exploited the vulnerability could impersonate processes, interject cross-process communication, or interrupt system functionality.
(CVE-2018-0748, CVE-2018-0751, CVE-2018-0752)

- An information disclosure vulnerability exists when the scripting engine does not properly handle objects in memory in Microsoft Edge. An attacker who successfully exploited the vulnerability could obtain information to further compromise the users system. (CVE-2018-0767, CVE-2018-0780)

- An elevation of privilege vulnerability exists in the Microsoft Server Message Block (SMB) Server when an attacker with valid credentials attempts to open a specially crafted file over the SMB protocol on the same machine. An attacker who successfully exploited this vulnerability could bypass certain security checks in the operating system. (CVE-2018-0749)

- A denial of service vulnerability exists in the way that Windows handles objects in memory. An attacker who successfully exploited the vulnerability could cause a target system to stop responding. Note that the denial of service condition would not allow an attacker to execute code or to elevate user privileges. However, the denial of service condition could prevent authorized users from using system resources. The security update addresses the vulnerability by correcting how Windows handles objects in memory. (CVE-2018-0753)
Solution/Mitigation
Apply Cumulative Update KB4056890 or KB4057142 as well as refer to the KB4072698 article for additional information.

Mitigation: 

 Mitigating this vulnerability requires you to make changes to the registry. Please backup your registry before any changes. Also the system needs to be restarted for the changes to take affect. If applying to  Hyper V host specific, please shutdown all virtual machines in the host before shutdown.  Also if the Hyper V Host has clustering enabled , the live migration of hosts from the fixed registry Hyper V to Non Fix Hyper V host may fail. So it is recommended to apply the fix simultaneously in all clustered Hyper V hosts


Registry Values Before Fix


Apply the below values in an admin command prompt or Powershell after backing up your registry 

reg add "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management" /v FeatureSettingsOverride /t REG_DWORD /d 0 /f
reg add "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management" /v FeatureSettingsOverrideMask /t REG_DWORD /d 3 /f




                                                                    Registry Values After Fix



After applying the fix the vulnerability is mitigated and will appear as mitigated in all Compliance scans

Thursday, September 20, 2018

KB4088880: Windows Server 2012 March 2018 Security Update



Tenable Plugin : Plugin #108292


Tenable output

  The following registry keys need to be set to the appropriate values as dictated in ADV180002.
  This is required to enable the fix for CVE-2017-5715, CVE-2017-5753, and CVE-2017-5754:

  SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\FeatureSettingsOverride
  SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\FeatureSettingsOverrideMask
  SOFTWARE\Microsoft\Windows NT\CurrentVersion\Virtualization\MinVmVersionForCpuBasedMitigations

  See KB Article 4072698 for more details.


Mitigation: 

 Mitigating this vulnerability requires you to make changes to the registry. Please backup your registry before any changes. Also the system needs to be restarted for the changes to take affect. Since this is Hyper V host specific, please shutdown all virtual machines in the host before shutdown.  Also if the Hyper V Host has clustering enabled , the live migration of hosts from the fixed registry Hyper V to Non Fix Hyper V host may fail. So it is recommended to apply the fix simultaneously in all clustered Hyper V hosts

To enable the fix:
reg add "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management" /v FeatureSettingsOverride /t REG_DWORD /d 0 /f
reg add "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management" /v FeatureSettingsOverrideMask /t REG_DWORD /d 3 /f
reg add "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Virtualization" /v MinVmVersionForCpuBasedMitigations /t REG_SZ /d "1.0" /f 


More details at

https://support.microsoft.com/en-us/help/4072698/windows-server-guidance-to-protect-against-the-speculative-execution

Note:

These posts are more focused towards being complaint in PCI and various other security scans. There are microcode available from respective chip vendors to mitigate this vulnerability but which is beyond the scop of this post  


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