This security update resolves the following vulnerabilities:
- A "remote code execution" vulnerability exists when .NET Framework does not validate input correctly. An attacker who successfully exploits this vulnerability could take control of an affected system. An attacker could then install programs; view, change, or delete data; or create new accounts that have full user rights. Users whose accounts are configured to have fewer user rights on the system could be less affected than users who have administrative user rights. To exploit the vulnerability, an attacker would have to pass specific input to an application through susceptible .NET Framework methods. This security update addresses the vulnerability by correcting how .NET Framework validates input. To learn more about this vulnerability, see Microsoft Common Vulnerabilities and Exposures CVE-2018-8284.
- An "elevation of privilege" vulnerability exists in .NET Framework that could allow an attacker to elevate their user rights level. To exploit the vulnerability, an attacker would first have to access the local computer, and then run a malicious program. This update addresses the vulnerability by correcting how .NET Framework enables COM objects. To learn more about this vulnerability, see Microsoft Common Vulnerabilities and Exposures CVE-2018-8202.
- A "security feature bypass" vulnerability exists when .NET Framework components do not correctly validate certificates. An attacker could present expired certificates when challenged. This security update addresses the vulnerability by making sure that .NET Framework components correctly validate certificates. To learn more about this vulnerability, see Microsoft Common Vulnerabilities and Exposures CVE-2018-8356.
- All updates for .NET Framework 4.6 for Windows Server 2008 require the d3dcompiler_47.dll update to be installed. We recommend that you install the included d3dcompiler_47.dll update before you apply this update. For more information about the d3dcompiler_47.dll update, see KB 4019478.
- If you install a language pack after you install this update, you must reinstall this update. Therefore, we recommend that you install any language packs that you need before you install this update. For more information, see Add language packs to Windows.
Additional information about this security update
- 4338422 Description of the Security and Quality Rollup updates for .NET Framework 2.0 SP2 and 3.0 SP2 for Windows Server 2008 (KB 4338422)
- 4338417 Description of the Security and Quality Rollup updates for .NET Framework 4.5.2 for Windows 7 SP1, Server 2008 R2 SP1, and Server 2008 (KB 4338417)
- 4338420 Description of the Security and Quality Rollup updates for .NET Framework 4.6, 4.6.1, 4.6.2, 4.7, and 4.7.1 for Windows 7 SP1 and Server 2008 R2 SP1, and for .NET Framework 4.6 for Server 2008 (KB 4338420)
After you install any of the July 2018 .NET Framework Security Updates, a COM component fails to load because of “access denied,” “class not registered,” or “internal failure occurred for unknown reasons” errors. The most common failure signature is the following:
Exception type: System.UnauthorizedAccessException
Message: Access is denied. (Exception from HRESULT: 0x80070005 (E_ACCESSDENIED))
For more information, see: KB 4345913.
How to obtain help and support for this security update
- Help for installing updates: Windows Update FAQ
- Security solutions for IT professionals: TechNet Security Support and Troubleshooting
- Help for protecting your Windows-based products and services from viruses and malware: Microsoft Secure
- Local support according to your country: International Support