.NET Framework Elevation of Privilege Vulnerability

Security Vulnerability

Released: Jul 10, 2018

Last updated: Aug 15, 2018

Assigning CNA
Microsoft
CVE.org link
CVE-2018-8202

Executive Summary

An elevation of privilege vulnerability exists in .NET Framework which could allow an attacker to elevate their privilege level.

To exploit the vulnerability, an attacker would first have to access the local machine, and then run a malicious program.

The update addresses the vulnerability by correcting how .NET Framework activates COM objects.

Exploitability

The following table provides an exploitability assessment for this vulnerability at the time of original publication.

Publicly disclosed
No
Exploited
No
Exploitability assessment
Exploitation Less Likely

FAQ

After I installed the July 2018 updates for .NET Framework, applications fail to start or are not working correctly. What do I need to do to remedy this situation?

Microsoft is aware of multiple customer reports of applications that fail to start or that do not run correctly. Please refer to the following Recommended Actions.

Recommended actions

Customers who have not installed security updates released on July 10 for .NET: Test the updates released on July 10, and if no application errors are found, apply the updates to production.

Customers who have successfully installed security updates released on July 10 for .NET and who are not experiencing any issues: No further action is required.

Customers who have installed security updates released on July 10 for .NET and who are experiencing application errors:

  1. Register for security notifications mailer to be alerted of any content changes to this advisory and notifications of new updates.  See Microsoft Technical Security Notifications.
  2. Assess the risk of application errors caused by the updates compared to vulnerability exposure risk:

Risk guidance:

Workstations and Terminal servers are the primary target systems where an attacker could have User level access to exploit the vulnerability. In web-application server scenarios, unprivileged users will not typically have system login access. As such, the attack surface is diminished.

  • If the risk of application errors is acceptable, then:
  1. Apply the security updates released on July 10 for .NET to workstations and non-web-application servers.
  2. Prepare to apply the forthcoming cumulative update, which no longer carries the application errors described in KB4345913. Customers will be notified via an update to this CVE when those updates are available.
  • If the risk of application errors is not acceptable, then:
  1. Remove the security updates released on July 10 for .NET from systems that are showing application errors.
  2. You will be notifed via an update to this CVE when a limited-distribution update is available in the following days. Apply it to affected web-application servers.

Acknowledgements

  • Lasse Trolle Borup of Langkjaer Cyber Defence
Microsoft recognizes the efforts of those in the security community who help us protect customers through coordinated vulnerability disclosure. See Acknowledgements for more information.

Security Updates

To determine the support lifecycle for your software, see the Microsoft Support Lifecycle.

Release date Descending

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

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