Microsoft Security Bulletin MS15-061 - Important

Vulnerabilities in Windows Kernel-Mode Drivers Could Allow Elevation of Privilege (3057839)

Published: June 9, 2015

Version: 1.0

Executive Summary

This security update resolves vulnerabilities in Microsoft Windows. The most severe of these vulnerabilities could allow elevation of privilege if an attacker logs on to the system and runs a specially crafted application. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.

This security update is rated Important for all supported releases of Windows. For more information, see the Affected Software section.

The security update addresses the vulnerabilities by correcting how the Windows kernel-mode driver handles objects in memory and validates user input. For more information about the vulnerabilities, see the Vulnerability Information section.

For more information about this update, see Microsoft Knowledge Base Article 3057839.

Affected Software

Operating System

Maximum Security Impact

Aggregate Severity Rating

Updates Replaced*

Windows Server 2003

Windows Server 2003 Service Pack 2
(3057839)

Elevation of Privilege

Important

3034344 in MS15-023

Windows Server 2003 x64 Edition Service Pack 2
(3057839)

Elevation of Privilege

Important

3034344 in MS15-023

Windows Server 2003 with SP2 for Itanium-based Systems
(3057839)

Elevation of Privilege

Important

3034344 in MS15-023

Windows Server 2003 R2 Service Pack 2
(3057839)

Elevation of Privilege

Important

3034344 in MS15-023

Windows Server 2003 R2 x64 Edition Service Pack 2
(3057839)

Elevation of Privilege

Important

3034344 in MS15-023

Windows Vista

Windows Vista Service Pack 2
(3057839)

Elevation of Privilege

Important

3034344 in MS15-023

Windows Vista x64 Edition Service Pack 2
(3057839)

Elevation of Privilege

Important

3034344 in MS15-023

Windows Server 2008

Windows Server 2008 for 32-bit Systems Service Pack 2
(3057839)

Elevation of Privilege

Important

3034344 in MS15-023

Windows Server 2008 for x64-based Systems Service Pack 2
(3057839)

Elevation of Privilege

Important

3034344 in MS15-023

Windows Server 2008 for Itanium-based Systems Service Pack 2
(3057839)

Elevation of Privilege

Important

3034344 in MS15-023

Windows 7

Windows 7 for 32-bit Systems Service Pack 1
(3057839)

Elevation of Privilege

Important

3034344 in MS15-023

Windows 7 for x64-based Systems Service Pack 1
(3057839)

Elevation of Privilege

Important

3034344 in MS15-023

Windows Server 2008 R2

Windows Server 2008 R2 for x64-based Systems Service Pack 1
(3057839)

Elevation of Privilege

Important

3034344 in MS15-023

Windows Server 2008 R2 for Itanium-based Systems Service Pack 1
(3057839)

Elevation of Privilege

Important

3034344 in MS15-023

Windows 8 and Windows 8.1

Windows 8 for 32-bit Systems
(3057839)

Elevation of Privilege

Important

3034344 in MS15-023

Windows 8 for x64-based Systems
(3057839)

Elevation of Privilege

Important

3034344 in MS15-023

Windows 8.1 for 32-bit Systems
(3057839)

Elevation of Privilege

Important

3034344 in MS15-023

Windows 8.1 for x64-based Systems
(3057839)

Elevation of Privilege

Important

3034344 in MS15-023

Windows Server 2012 and Windows Server 2012 R2

Windows Server 2012
(3057839)

Elevation of Privilege

Important

3034344 in MS15-023

Windows Server 2012 R2
(3057839)

Elevation of Privilege

Important

3034344 in MS15-023

Windows RT and Windows RT 8.1

Windows RT[1] (3057839)

Elevation of Privilege

Important

3034344 in MS15-023

Windows RT 8.1[1] (3057839)

Elevation of Privilege

Important

3034344 in MS15-023

Server Core installation option

Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation)
(3057839)

Elevation of Privilege

Important

3034344 in MS15-023

Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation)
(3057839)

Elevation of Privilege

Important

3034344 in MS15-023

Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation)
(3057839)

Elevation of Privilege

Important

3034344 in MS15-023

Windows Server 2012 (Server Core installation)
(3057839)

Elevation of Privilege

Important

3034344 in MS15-023

Windows Server 2012 R2 (Server Core installation)
(3057839)

Elevation of Privilege

Important

3034344 in MS15-023

Note The update is available for Windows Technical Preview and Windows Server Technical Preview. Customers running these operating systems are encouraged to apply the update, which is available via Windows Update.

[1]This update is available via Windows Update only.

*The Updates Replaced column shows only the latest update in a chain of superseded updates. For a comprehensive list of updates replaced, go to the Microsoft Update Catalog, search for the update KB number, and then view update details (updates replaced information is on the Package Details tab).

Severity Ratings and Vulnerability Identifiers

The following severity ratings assume the potential maximum impact of the vulnerability. For information regarding the likelihood, within 30 days of this security bulletin's release, of the exploitability of the vulnerability in relation to its severity rating and security impact, please see the Exploitability Index in the June bulletin summary.

Severity Ratings and Vulnerability Identifiers (Table 1 of 2)

Vulnerability Severity Rating and Maximum Security Impact by Affected Software

Affected Software

Microsoft Windows Kernel Information Disclosure Vulnerability – CVE-2015-1719

Microsoft Windows Kernel Use After Free Vulnerability – CVE-2015-1720

Win32k Null Pointer Dereference Vulnerability - CVE-2015-1721

Microsoft Windows Kernel Bitmap Handling Use After Free Vulnerability - CVE-2015-1722

Microsoft Windows Station Use After Free Vulnerability - CVE-2015-1723

Aggregate Severity Rating

Windows Server 2003

Windows Server 2003 Service Pack 2
(3057839)

Important
Information Disclosure

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important

Windows Server 2003 x64 Edition Service Pack 2
(3057839)

Important
Information Disclosure

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important

Windows Server 2003 with SP2 for Itanium-based Systems
(3057839)

Important
Information Disclosure

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important

Windows Server 2003 R2 Service Pack 2
(3057839)

Important
Information Disclosure

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important

Windows Server 2003 R2 x64 Edition Service Pack 2
(3057839)

Important
Information Disclosure

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important

Windows Vista

Windows Vista Service Pack 2
(3057839)

Important
Information Disclosure

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important

Windows Vista x64 Edition Service Pack 2
(3057839)

Important
Information Disclosure

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important

Windows Server 2008

Windows Server 2008 for 32-bit Systems Service Pack 2
(3057839)

Important
Information Disclosure

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important

Windows Server 2008 for x64-based Systems Service Pack 2
(3057839)

Important
Information Disclosure

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important

Windows Server 2008 for Itanium-based Systems Service Pack 2
(3057839)

Important
Information Disclosure

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important

Windows 7

Windows 7 for 32-bit Systems Service Pack 1
(3057839)

Important
Information Disclosure

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important

Windows 7 for x64-based Systems Service Pack 1
(3057839)

Important
Information Disclosure

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important

Windows Server 2008 R2

Windows Server 2008 R2 for x64-based Systems Service Pack 1
(3057839)

Important
Information Disclosure

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important

Windows Server 2008 R2 for Itanium-based Systems Service Pack 1
(3057839)

Important
Information Disclosure

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important

Windows 8 and Windows 8.1

Windows 8 for 32-bit Systems
(3057839)

Important
Information Disclosure

Important
Elevation of Privilege

Moderate
Denial of Service

Important
Elevation of Privilege

Important
Elevation of Privilege

Important

Windows 8 for x64-based Systems
(3057839)

Important
Information Disclosure

Important
Elevation of Privilege

Moderate
Denial of Service

Important
Elevation of Privilege

Important
Elevation of Privilege

Important

Windows 8.1 for 32-bit Systems
(3057839)

Important
Information Disclosure

Important
Elevation of Privilege

Moderate
Denial of Service

Important
Elevation of Privilege

Important
Elevation of Privilege

Important

Windows 8.1 for x64-based Systems
(3057839)

Important
Information Disclosure

Important
Elevation of Privilege

Moderate
Denial of Service

Important
Elevation of Privilege

Important
Elevation of Privilege

Important

Windows Server 2012 and Windows Server 2012 R2

Windows Server 2012
(3057839)

Important
Information Disclosure

Important
Elevation of Privilege

Moderate
Denial of Service

Important
Elevation of Privilege

Important
Elevation of Privilege

Important

Windows Server 2012 R2
(3057839)

Important
Information Disclosure

Important
Elevation of Privilege

Moderate
Denial of Service

Important
Elevation of Privilege

Important
Elevation of Privilege

Important

Windows RT and Windows RT 8.1

Windows RT
(3057839)

Important
Information Disclosure

Important
Elevation of Privilege

Moderate
Denial of Service

Important
Elevation of Privilege

Important
Elevation of Privilege

Important

Windows RT 8.1
(3057839)

Important
Information Disclosure

Important
Elevation of Privilege

Moderate
Denial of Service

Important
Elevation of Privilege

Important
Elevation of Privilege

Important

Server Core installation option

Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation)
(3057839)

Important
Information Disclosure

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important

Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation)
(3057839)

Important
Information Disclosure

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important

Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation)
(3057839)

Important
Information Disclosure

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important

Windows Server 2012 (Server Core installation)
(3057839)

Important
Information Disclosure

Important
Elevation of Privilege

Moderate
Denial of Service

Important
Elevation of Privilege

Important
Elevation of Privilege

Important

Windows Server 2012 R2 (Server Core installation)
(3057839)

Important
Information Disclosure

Important
Elevation of Privilege

Moderate
Denial of Service

Important
Elevation of Privilege

Important
Elevation of Privilege

Important

Severity Ratings and Vulnerability Identifiers (Table 2 of 2)

Vulnerability Severity Rating and Maximum Security Impact by Affected Software

Affected Software

Microsoft Windows Kernel Object Use After Free Vulnerability - CVE-2015-1724

Win32k Buffer Overflow Vulnerability - CVE-2015-1725

Microsoft Windows Kernel Brush Object Use After Free Vulnerability - CVE-2015-1726

Win32k Pool Buffer Overflow Vulnerability - CVE-2015-1727

Win32k Memory Corruption Elevation of Privilege Vulnerability - CVE-2015-1768

Win32k Elevation of Privilege Vulnerability - CVE-2015-2360

Aggregate Severity Rating

Windows Server 2003

Windows Server 2003 Service Pack 2
(3057839)

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important

Windows Server 2003 x64 Edition Service Pack 2
(3057839)

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important

Windows Server 2003 with SP2 for Itanium-based Systems
(3057839)

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important

Windows Server 2003 R2 Service Pack 2
(3057839)

Important
Information Disclosure

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important

Windows Server 2003 R2 x64 Edition Service Pack 2
(3057839)

Important
Information Disclosure

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important

Windows Vista

Windows Vista Service Pack 2
(3057839)

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

None

Important
Elevation of Privilege

Important

Windows Vista x64 Edition Service Pack 2
(3057839)

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

None

Important
Elevation of Privilege

Important

Windows Server 2008

Windows Server 2008 for 32-bit Systems Service Pack 2
(3057839)

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

None

Important
Elevation of Privilege

Important

Windows Server 2008 for x64-based Systems Service Pack 2
(3057839)

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

None

Important
Elevation of Privilege

Important

Windows Server 2008 for Itanium-based Systems Service Pack 2
(3057839)

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

None

Important
Elevation of Privilege

Important

Windows 7

Windows 7 for 32-bit Systems Service Pack 1
(3057839)

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

None

Important
Elevation of Privilege

Important

Windows 7 for x64-based Systems Service Pack 1
(3057839)

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

None

Important
Elevation of Privilege

Important

Windows Server 2008 R2

Windows Server 2008 R2 for x64-based Systems Service Pack 1
(3057839)

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

None

Important
Elevation of Privilege

Important

Windows Server 2008 R2 for Itanium-based Systems Service Pack 1
(3057839)

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

None

Important
Elevation of Privilege

Important

Windows 8 and Windows 8.1

Windows 8 for 32-bit Systems
(3057839)

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

None

Important
Elevation of Privilege

Important

Windows 8 for x64-based Systems
(3057839)

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

None

Important
Elevation of Privilege

Important

Windows 8.1 for 32-bit Systems
(3057839)

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

None

Important
Elevation of Privilege

Important

Windows 8.1 for x64-based Systems
(3057839)

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

None

Important
Elevation of Privilege

Important

Windows Server 2012 and Windows Server 2012 R2

Windows Server 2012
(3057839)

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

None

Important
Elevation of Privilege

Important

Windows Server 2012 R2
(3057839)

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

None

Important
Elevation of Privilege

Important

Windows RT and Windows RT 8.1

Windows RT
(3057839)

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

None

Important
Elevation of Privilege

Important

Windows RT 8.1
(3057839)

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

None

Important
Elevation of Privilege

Important

Server Core installation option

Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation)
(3057839)

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

None

Important
Elevation of Privilege

Important

Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation)
(3057839)

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

None

Important
Elevation of Privilege

Important

Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation)
(3057839)

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

None

Important
Elevation of Privilege

Important

Windows Server 2012 (Server Core installation)
(3057839)

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

None

Important
Elevation of Privilege

Important

Windows Server 2012 R2 (Server Core installation)
(3057839)

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

Important
Elevation of Privilege

None

Important
Elevation of Privilege

Important

Vulnerability Information

Microsoft Windows Kernel Information Disclosure Vulnerability – CVE-2015-1719

An information disclosure vulnerability exists when the Windows kernel-mode driver improperly handles buffer elements under certain conditions, allowing an attacker to request the contents of specific memory addresses. An attacker who successfully exploited this vulnerability could then potentially read data that is not intended to be disclosed. 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 in an attempt to further compromise the affected system. Workstations and servers are primarily at risk. Servers could be at more risk if administrators allow users to log on to servers and to run programs. However, best practices strongly discourage this.

To exploit this vulnerability an attacker must have valid logon credentials and be able to execute programs on the system. The security update addresses the vulnerability by correcting how the Windows kernel-mode driver validates memory addresses.

Microsoft received information about this vulnerability through coordinated vulnerability disclosure. When this security bulletin was originally issued Microsoft had not received any information to indicate that this vulnerability had been publicly used to attack customers.

Mitigating Factors

The following mitigating factors may be helpful in your situation:

  • An attacker must have valid logon credentials and be able to log on locally to exploit this vulnerability.

Workarounds

Microsoft has not identified any workarounds for this vulnerability.

Microsoft Windows Kernel Use After Free Vulnerability – CVE-2015-1720

An elevation of privilege vulnerability exists when the Windows kernel-mode driver improperly frees an object in memory that an attacker could use to execute arbitrary code with elevated permissions. 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 administrative rights.

To exploit this vulnerability an attacker would first have to log on to the system or convince a logged-on user to execute a specially crafted application. Workstations and terminal servers are primarily at risk. The update addresses the vulnerability by changing how certain objects are handled in memory.

Microsoft received information about this vulnerability through coordinated vulnerability disclosure. When this security bulletin was originally issued Microsoft had not received any information to indicate that this vulnerability had been publicly used to attack customers.

Mitigating Factors

The following mitigating factors may be helpful in your situation:

  • An attacker must have valid logon credentials and be able to log on locally to exploit this vulnerability.

Workarounds

Microsoft has not identified any workarounds for this vulnerability.

Win32k Null Pointer Dereference Vulnerability - CVE-2015-1721

An elevation of privilege vulnerability exists in the Windows kernel-mode driver due to insufficient validation of certain data passed from user mode. 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.

To exploit this vulnerability, an attacker would first have to log on to the system. An attacker could then run a specially crafted application designed to increase privileges. The update addresses the vulnerability by ensuring that the kernel-mode driver properly validates data passed from user mode.

Microsoft received information about this vulnerability through coordinated vulnerability disclosure. When this security bulletin was originally issued Microsoft had not received any information to indicate that this vulnerability had been publicly used to attack customers.

Mitigating Factors

Microsoft has not identified any mitigating factors for this vulnerability.

Workarounds

The following workarounds may be helpful in your situation:

  • Disable NULL page mapping on Windows 7
    Note This workaround only applies to Windows 7.

    1. Click Start, click Run, in the Open box type regedit, and then click OK.
    2. Locate and then click the following registry subkey:

          HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management
      
    3. On the Edit menu, point to New, and then click DWORD.

    4. Type EnableLowVaAccess, and then press Enter.
    5. On the Edit menu, click Modify to modify the EnableLowAvAccess registry entry.
    6. In the Valuedata box, type 0, and then click OK.
    7. Exit Registry Editor.
    8. Restart the system.

    Impact of workaround. A restart is required. Some 16-bit applications may not work as expected.

    How to undo the workaround.

    1. Click Start, click Run, in the Open box type regedit, and then click OK.
    2. Locate and then click the following registry subkey:

          HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management
      
    3. On the Edit menu, click Delete on the EnableLowAvAccess registry entry.

    4. On the dialog box, click YES.
    5. Exit Registry Editor.
    6. Restart the system.

Multiple Microsoft Windows Kernel Vulnerabilities

Multiple elevation of privilege vulnerabilities exist in the Windows kernel-mode driver when it accesses an object in memory that has either not been correctly initialized or deleted. The vulnerabilities may corrupt memory in such a way that an attacker could gain elevated privileges on a targeted system.

An authenticated attacker who successfully exploited these vulnerabilities could acquire elevated privileges. An attacker could then install programs; view, change, or delete data; or create new accounts with full administrative rights.

To exploit the vulnerabilities, an attacker would first have to log on to the system. An attacker could then run a specially crafted application designed to increase privileges. The update addresses the vulnerabilities by correcting how the kernel-mode driver handles objects in memory.

Vulnerability title CVE number Publicly disclosed Exploited
Microsoft Windows Kernel Bitmap Handling Use After Free Vulnerability CVE-2015-1722 No No
Microsoft Windows Station Use After Free Vulnerability CVE-2015-1723 No No
Microsoft Windows Kernel Object Use After Free Vulnerability CVE-2015-1724 No No
Microsoft Windows Kernel Brush Object Use After Free Vulnerability CVE-2015-1726 No No

Mitigating Factors

The following mitigating factors may be helpful in your situation:

  • An attacker must have valid logon credentials and be able to log on locally to exploit this vulnerability.

Workarounds

Microsoft has not identified any workarounds for this vulnerability.

Multiple Windows Kernel Buffer Overflow Vulnerabilities

Multiple elevation of privilege vulnerabilities exist in the Windows kernel-mode driver when it improperly validates user input. An attacker who successfully exploited these vulnerabilities could gain elevated privileges on a targeted system.

An authenticated attacker who successfully exploited these vulnerabilities could acquire elevated privileges. An attacker could then install programs; view, change, or delete data; or create new accounts with full administrative rights.

To exploit these vulnerabilities, an attacker would first have to log on to the system. An attacker could then run a specially crafted application designed to increase privileges. The update addresses the vulnerabilities by correcting how the kernel-mode driver validates user input.

Vulnerability title CVE number Publicly disclosed Exploited
Win32k Buffer Overflow Vulnerability CVE-2015-1725 No No
Win32k Pool Buffer Overflow Vulnerability CVE-2015-1727 No No

Mitigating Factors

The following mitigating factors may be helpful in your situation:

  • An attacker must have valid logon credentials and be able to log on locally to exploit this vulnerability.

Workarounds

The following workarounds may be helpful in your situation:

  • Disable NULL page mapping on Windows 7
    Note This workaround only applies to Windows 7.

    1. Click Start, click Run, in the Open box type regedit, and then click OK.
    2. Locate and then click the following registry subkey:

      
          HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management
      
    3. On the Edit menu, point to New, and then click DWORD.

    4. Type EnableLowVaAccess, and then press Enter.
    5. On the Edit menu, click Modify to modify the EnableLowAvAccess registry entry.
    6. In the Value data box, type 0, and then click OK.
    7. Exit Registry Editor.
    8. Restart the system.

    Impact of workaround. A restart is required. Some 16-bit applications may not work as expected.

    How to undo the workaround.

    1. Click Start, click Run, in the Open box type regedit, and then click OK.
    2. Locate and then click the following registry subkey:

      
          HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management
      
    3. On the Edit menu, click Delete on the EnableLowAvAccess registry entry.

    4. On the dialog box, click YES.
    5. Exit Registry Editor.
    6. Restart the system.

Multiple Win32k Memory Corruption Elevation of Privilege Vulnerabilities

An elevation of privilege vulnerability exists when the Windows kernel-mode driver, Win32k.sys, fails to properly free memory. An attacker who successfully exploited this vulnerability could execute arbitrary code within the context of another user. If that other user has elevated rights, an attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.

To exploit this vulnerability, an attacker would first have to log on to the system. An attacker could then run a specially crafted application designed to increase privileges. The update addresses the vulnerability by correcting how that the Windows kernel-mode driver handles objects in memory.

Vulnerability title CVE number Publicly disclosed Exploited
Win32k Memory Corruption Elevation of Privilege Vulnerability CVE-2015-1768 No No
Win32k Elevation of Privilege Vulnerability CVE-2015-2360 No Yes

Mitigating Factors

The following mitigating factors may be helpful in your situation:

  • An attacker must have valid logon credentials and be able to log on locally to exploit this vulnerability.

Workarounds

Microsoft has not identified any workarounds for this vulnerability.

Acknowledgments

Microsoft recognizes the efforts of those in the security community who help us protect customers through coordinated vulnerability disclosure. See Acknowledgments for more information.

Disclaimer

The information provided in the Microsoft Knowledge Base is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.

Revisions

  • V1.0 (June 9, 2015): Bulletin published.

Page generated 2015-06-16 11:27Z-07:00.