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Rewterz Threat Alert – Bitter APT Threat Actors – Active IOCs
January 17, 2023
Rewterz Threat Advisory – Multiple Microsoft Windows Internet Key Exchange (IKE) Extension Vulnerabilities
January 17, 2023

Rewterz Threat Advisory – Multiple Microsoft Windows Layer 2 Tunneling Protocol (L2TP) Vulnerabilities

January 17, 2023

Severity

High

Analysis Summary

CVE-2023-21757 CVSS:7.5

Microsoft Windows is vulnerable to a denial of service, caused by a flaw in the Layer 2 Tunneling Protocol (L2TP). By sending a specially-crafted request, a remote attacker could exploit this vulnerability to cause a denial of service condition.

CVE-2023-21555 CVSS:8.1

Microsoft Windows could allow a remote attacker to execute arbitrary code on the system, caused by a flaw in the Layer 2 Tunneling Protocol (L2TP). By sending a specially-crafted request to a RAS server, an attacker could exploit this vulnerability to execute arbitrary code on the RAS server machine.

CVE-2023-21546 CVSS:8.1

Microsoft Windows could allow a remote attacker to execute arbitrary code on the system, caused by a flaw in the Layer 2 Tunneling Protocol (L2TP). By sending a specially-crafted request to a RAS server, an attacker could exploit this vulnerability to execute arbitrary code on the RAS server machine.

CVE-2023-21679 CVSS:8.1

Microsoft Windows could allow a remote attacker to execute arbitrary code on the system, caused by a flaw in the Layer 2 Tunneling Protocol (L2TP). By sending a specially-crafted request to a RAS server, an attacker could exploit this vulnerability to execute arbitrary code on the RAS server machine.

CVE-2023-21556 CVSS:8.1

Microsoft Windows could allow a remote attacker to execute arbitrary code on the system, caused by a flaw in the Layer 2 Tunneling Protocol (L2TP). By sending a specially-crafted request to a RAS server, an attacker could exploit this vulnerability to execute arbitrary code on the RAS server machine.

CVE-2023-21543 CVSS:8.1

Microsoft Windows could allow a remote attacker to execute arbitrary code on the system, caused by a flaw in the Layer 2 Tunneling Protocol (L2TP). By sending a specially-crafted request to a RAS server, an attacker could exploit this vulnerability to execute arbitrary code on the RAS server machine.

Impact

  • Denial of Service
  • Code Execution

Indicators Of Compromise

CVE

  • CVE-2023-21757
  • CVE-2023-21555
  • CVE-2023-21546
  • CVE-2023-21679
  • CVE-2023-21556
  • CVE-2023-21543

Affected Vendors

Microsoft

Affected Products

  • Microsoft Windows 7 SP1 x32
  • Microsoft Windows 7 SP1 x64
  • Microsoft Windows Server 2012
  • Microsoft Windows 8.1 x32
  • Microsoft Windows 8.1 x64
  • Microsoft Windows Server 2012 R2
  • Microsoft Windows RT 8.1Microsoft Windows 10 x32
  • Microsoft Windows 10 x64
  • Microsoft Windows Server 2016Microsoft Windows Server 2019
  • Microsoft Windows 10 1809 for x64-based Systems
  • Microsoft Windows 10 1809 for 32-bit Systems
  • Microsoft Windows 10 1809 for ARM64-based Systems
  • Microsoft Windows 10 1607 for 32-bit Systems
  • Microsoft Windows 10 1607 for x64-based Systems
  • Microsoft Windows 10 20H2 for 32-bit Systems
  • Microsoft Windows 10 20H2 for ARM64-based Systems
  • Microsoft Windows 10 20H2 for x64-based Systems
  • Microsoft Windows Server (Server Core installation) 2019
  • Microsoft Windows Server (Server Core installation) 2016
  • Microsoft Windows Server (Server Core installation) 2012 R2
  • Microsoft Windows Server (Server Core installation) 2012
  • Microsoft Windows Server for X64-based systems 2008 R2 SP1
  • Microsoft Windows Server for X64-based systems (Server Core installation) 2008 SP2
  • Microsoft Windows Server for 32-bit systems (Server Core installation) 2008 SP2
  • Microsoft Windows Server for 32-bit systems 2008 SP2Microsoft Windows Server 2022
  • Microsoft Windows Server (Server Core installation) 2022
  • Microsoft Windows Server for X64-based systems 2008 SP2
  • Microsoft Windows 10 21H2 for 32-bit Systems
  • Microsoft Windows 10 21H2 for ARM64-based Systems
  • Microsoft Windows 10 21H2 for x64-based Systems
  • Microsoft Windows Server 2022 Azure Edition Core Hotpatch
  • Microsoft Windows 11 22H2 for ARM64-based Systems
  • Microsoft Windows 11 22H2 for x64-based Systems
  • Microsoft Windows 10 22H2 for 32-bit Systems
  • Microsoft Windows 10 22H2 for ARM64-based Systems
  • Microsoft Windows 10 22H2 for x64-based Systems
  • Microsoft Windows 11 21H2 for ARM64-based Systems
  • Microsoft Windows 11 21H2 for x64-based Systems
  • Microsoft Windows Server for X64-based systems (Server Core installation) 2008 R2

Remediation

Use Microsoft Automatic Update to apply the appropriate patch for your system, or the Microsoft Security Update Guide to search for available patches.

CVE-2023-21757

CVE-2023-21555

CVE-2023-21546

CVE-2023-21679

CVE-2023-21556

CVE-2023-21543

  • Services
    • Assess
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    • Respond
      • Incident Response
      • Incident Analysis
  • Transform
    • SOC Consultancy
    •     SOC Maturity Assessment
    •     SOC Model Evaluation
    •     SOC Gap Analysis
    •     SIEM Gap Analysis
    •     SIEM Optimization
    •     SOC Content Pack
  • Train
    • Security Awareness and Training
    • Tabletop Exercise
    • Simulated Cyber Attack Exercises
  • Managed Security
    • Managed Security Monitoring
      • Remote SOC
      • Onsite SOC
      • Hybrid SOC
    • Managed Security Services
      • Managed Detection and Response
      • Managed Endpoint Detection and Response
      • Managed Threat Intelligence
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      • Managed Risk-Based SOAR
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  • Solutions
  • Resources
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    • Threat Advisory
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    • About Us
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    • Contact
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