Issue Description

ES Manager shows that the endpoint requires a patching (KB 5016629), but when clicked on Patch it shows "Patching failed"

Error/Warning Information

Handling Process

We can refer to several logs when troubleshooting vulnerability patching issues.

1. Download Log – This is the log where we can see the agent downloads particular KB patch from the download server.

C:\Program Files\SF\EDR\agent\var\log\sfpatch\patch\down\

2. Install Log – Here we can see the agent tries to install the downloaded .cab patch using Windows built-in DISM tool.

C:\Program Files\SF\EDR\agent\var\log\sfpatch\patch\install\

3. Patch log – This is a general log that briefly shows the combination of download and installation of the KB patch.

C:\Program Files\SF\EDR\agent\var\log\sfpatch\patch

4. DISM log – The agent installs patch using the Windows DISM command.

C:\Windows\Logs\DISM\

5. CBS Log – This log shows all the changes made on the Windows system file.

C:\Windows\Logs\CBS\CBS.log

6. Download the patch installer (.msu) from Microsoft Catalog portal and try to install manually but failed.

7. Retrieve the currently installed patch details (cmd > systeminfo.exe) and compare with the patch details on MS Catalog.

8. Confirmed that the PC had already installed a newer KB patch (KB 5026368) that had replaced the patch (KB 5016629).

Root Cause

PC had already installed a newer KB patch (KB 5026368) that had replaced the patch (KB 5016629)

Solution

1. Windows default logs does not provide a clear error message when the patch failedto install due to existing patch had replaced the patch shown in ES Manager.

2. ES Mgr is not aware of the newer patch released by Microsoft that has replaced the older patch.

3. In this case, mark the vulnerability as ‘Ignore’ as the patch is no longer required.

Suggestions

Link to MS Catalog:

https://www.catalog.update.microsoft.com/

ES 3.7.12R2