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Overview

The WSUS command enumerates Windows Server Update Services (WSUS) client configuration. WSUS is Microsoft’s enterprise update management solution. Understanding WSUS configuration reveals the update infrastructure, which can be a target for exploitation (WSUS MitM attacks) or indicates the patch management posture of the environment.

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Syntax

Seatbelt.exe WSUS

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Remote Execution

Seatbelt.exe WSUS -computername=TARGET.domain.com [-username=DOMAIN\user -password=pass]

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Output

Returns WSUS configuration:
  • WSUS server URL
  • WSUS status server URL
  • Use WSUS server (enabled/disabled)
  • Update service configuration
  • Automatic update settings
  • Last successful sync time
  • Proxy configuration

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Use Cases

  • Red Team
  • Blue Team
  • Identify WSUS infrastructure for MitM attacks
  • Check if WSUS uses HTTP (exploitable)
  • Discover update management servers
  • Assess patch deployment mechanism
  • Plan WSUS exploitation (if HTTP)
  • Understand update infrastructure

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Example Output

====== WSUS ======

[*] WSUS Client Configuration:

UseWUServer              : 1 (Enabled)
WUServer                 : http://wsus.corp.local:8530
WUStatusServer           : http://wsus.corp.local:8530
[!] WARNING: WSUS using HTTP (vulnerable to MitM attacks)

UpdateServiceUrlAlternate:
TargetGroup              : Workstations
TargetGroupEnabled       : 1

Automatic Updates:
  AUOptions              : 4 (Auto download and schedule install)
  ScheduledInstallDay    : 0 (Every day)
  ScheduledInstallTime   : 3 (3:00 AM)
  NoAutoUpdate           : 0 (Auto update enabled)

Last Successful Sync     : 10/15/2024 3:00:00 AM

Proxy Configuration:
  ProxyServer            :
  ProxyBypass            :
Example with HTTPS (secure): 
====== WSUS ======

[*] WSUS Client Configuration:

UseWUServer              : 1 (Enabled)
WUServer                 : https://wsus.corp.local:8531
WUStatusServer           : https://wsus.corp.local:8531
[*] WSUS using HTTPS (secure)

UpdateServiceUrlAlternate:
TargetGroup              : Servers-Production
TargetGroupEnabled       : 1

Automatic Updates:
  AUOptions              : 3 (Auto download and notify for install)
  NoAutoUpdate           : 0 (Auto update enabled)

Last Successful Sync     : 10/15/2024 2:00:00 AM

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Remote Execution

This command supports remote execution using the -computername parameter.

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Detection Considerations

Low detection risk - reads WSUS registry configuration.
  • Registry Access: Queries HKLM\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate
  • WMI Activity: Remote execution generates WMI events

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WSUS Security Risks

WSUS over HTTP is a critical security vulnerability.
Attack Vector: When WSUS uses HTTP instead of HTTPS, attackers can perform Man-in-the-Middle (MitM) attacks to:
  1. Intercept Update Traffic
    • Position on network between client and WSUS server
    • Intercept HTTP update requests
  2. Inject Malicious Updates
    • Serve malicious executables as “updates”
    • Gain SYSTEM-level code execution
    • Deploy across entire environment
  3. Requirements for Attack:
    • WSUS using HTTP (not HTTPS)
    • Network position between client and server
    • ARP spoofing or routing control
Indicators:
  • WUServer URL starts with http:// instead of https://
  • Port 8530 (HTTP) instead of 8531 (HTTPS)
  • No SSL/TLS encryption
Tools:
  • WSUSpendu
  • PyWSUS
  • Custom MitM tools

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Defensive Recommendations

Critical Controls:
  1. Use HTTPS Only
    • Configure WSUS server for SSL
    • Update clients to use HTTPS URLs
    • Port 8531 for HTTPS vs 8530 for HTTP
  2. Network Segmentation
    • Separate WSUS traffic on dedicated VLAN
    • Restrict WSUS server access
    • Implement network access controls
  3. Monitoring
    • Alert on WSUS configuration changes
    • Monitor for HTTP WSUS usage
    • Track update deployment patterns
    • Log WSUS client connections
  4. Validation
    • Regularly audit WSUS client settings
    • Verify HTTPS enforcement
    • Check certificate validity
    • Review GPO configurations
Registry Keys to Monitor:
HKLM\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate
  - WUServer
  - WUStatusServer
  - UseWUServer

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Configuration Values

Automatic Update Options (AUOptions):
  • 1 - Keep my computer up to date is disabled
  • 2 - Notify before download
  • 3 - Auto download and notify for install
  • 4 - Auto download and schedule install
  • 5 - Allow local admin to select settings