Mar 16

A critical vulnerability in CredSSP was found that affects RDP and WinRM in all Windows versions

A remote code execution vulnerability in CredSSP provider have been found recently (CVE-2018-0886). It affects RDP and WinRM on all supported Windows versions. An attacker who successfully exploits this vulnerability could relay user credentials to execute code on the target system. Any application that depends on CredSSP for authentication may be vulnerable to this type of attack.You can find more information here:Security Advisory: Critical Vulnerability in CredSSP Allows Remote Code Execution on Servers Through MS-RDP (Video).

It requires the attacker to have access to your network first. But take it seriously – patch your systems.

The fix does not have its own but instead it was included in various KBs:

CVE-2018-0886 | CredSSP Remote Code Execution Vulnerability

The patch was included in March’s patch Tuesday so many Windows Update ready computers should be safe now.

Microsoft plans to make graceful transition from vulnerable to mitigated state of the protocol so clients have time to update and check compatibility/stability. They will release three updates to mitigate the issue:

1) First patch will fix the issueby correcting how CredSSPvalidates requests during the authentication process. The update will introduce a new registry key (and a group policy option Encryption Oracle Remediation) that will change the behavior of CredSSP clients and servers. It was already released on March 13, 2018

Administrators are encouraged toapply the policy and set it to “Force updated clients” or “Mitigated” on client and server computers as soon as possible. These changes will require a reboot of the affected systems

2) On April 17, 2018 Microsoft will release an update to RDP Client (MSTSC) that will enhance the error message that is presented when an updated client fails to connect to a server that has not been updated

3) On May 8, 2018 an update will be released to change the default setting from Vulnerable to Mitigated

The Patch Lady explains everything in details.

Go, patch and configure your systems guys 🙂

Mar 14

Your devices may not receive any Windows security updates as of January 2018

UPDATE: March patches relax antivirus restrictions.

If you’ve not been offered any security updates since January there’s a reason. It appears that some Antivirus programs make unsupported API calls to Windows kernel memory that interfere with January’s updates (especially Meltdown and Spectre patches) and may lead to BSoDs (Blue Screen of Death). To protect customers Microsoft have stopped offering security updates to devices with unsupported AVs.

While waiting for a fix from AV vendors (and if you’re absolutely sure you know what you’re doing) you can temporarily disable the compatibility check. The fix is just a registry key:

According to Microsoft as of March 13-th most of the AV vendors have fixed their products so the compatibility check will be removed soon.

You can find more information here:

Mar 13

Error: Unable to find resource while trying to upgrade to Windows 10 1709 Enterprise through WSUS

While upgrading to Windows 10 1709 Enterprise via WSUS your clients may report the following error:

(Unable to find resource):ReportingEvent.Client.167; Parameters: Feature update to Windows 10 (business editions), version 1709, en-us

This may happen to other versions too

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Feb 12

PowerShell™ Notes for Professionals & other books

Stack Overflow used to run an interesting project – Stack Overflow Documentation. It is currently shut down, but thanks to it we now have interesting free books like “PowerShell™ Notes for Professionals book“:

Please keep in mind it was created by SO content that may not be very accurate, like what I’d recently discovered:Are the cmdlets in a pipeline executing in parallel?

Anyway I’d recommend it since it contains an essentials compilation of PowerShell common tasks and language specifics.Good reading indeed!

There are also other books that may catch your interest:

Feb 12

How force your laptop to use GPU enabled card instead of Intel HD Graphics adapter

Windows Fall Creator’s Update for windows 10 have introduced one very neat feature: GPU tabs & other GPU related information in Task Manager:

Pretty nice indeed!

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Feb 08

Hyper-V error: External Ethernet adapter XYZ is already bound to the Microsoft Virtual Switch protocol

When you try to add a new vSwitch that is bound to a physical adapter in Hyper-V, you may receive the following error:

In this case go to network settings and find the affected adapter. Then in Properties remove the checkbox that binds Microsoft Virtual Switch protocol and press OK.

Try to create the vSwitch again.

Jan 10

Dynamic Objects in Active Directory

Sometimes we need to create users/groups/computers in Active Directory that will be used temporary (by a contractor, for testing etc.). The typical workflow is: Create > Use for a while > Delete. The deletion is manual and often these objects are being forgotten which poses some security risks.

It is little known fact that we can create the so called Dynamic objects (DOs, a.k.a. temporary objects) that get deleted from AD automatically when the associated TTL expires. Microsoft added this capability in Windows Server 2003. In fact the “Dynamic object” is an auxiliary class (OID = When linked to an object it adds some new attributes like the entryTTL (Entry-TTL) and ms-DS-Entry-Time-To-Die attribute.

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