Siemens SCALANCE W1750D

1. EXECUTIVE SUMMARY

• CVSS v3 9.8
• ATTENTION: Exploitable remotely/low attack complexity 
• Vendor: Siemens 
• Equipment: SCALANCE W1750D 
• Vulnerabilities: Uncontrolled Resource Consumption, Buffer Copy without Checking Size of Input, Improper Neutralization of Input During Web Page Generation, Improper Neutralization of Special Elements used in a Command, Improper Input Validation 

2. RISK EVALUATION

Successful exploitation of these vulnerabilities could allow an attacker to inject commands or exploit buffer overflow vulnerabilities, which could lead to denial of service, unauthenticated remote code execution. or stored XSS. 

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

Siemens reports these vulnerabilities affect the following versions of SCALANCE W1750D, which is a brand-labeled access point device from Aruba: 

• SCALANCE W1750D (JP) (6GK5750-2HX01-1AD0): All versions 
• SCALANCE W1750D (ROW) (6GK5750-2HX01-1AA0): All versions 
• SCALANCE W1750D (USA) (6GK5750-2HX01-1AB0): All versions 

3.2 VULNERABILITY OVERVIEW

3.2.1 UNCONTROLLED RESOURCE CONSUMPTION CWE-400 

The Diffie-Hellman Key Agreement Protocol allows remote attackers (from the client side) to send arbitrary numbers (not actual public keys) and trigger expensive server-side DHE modular-exponentiation calculations, aka a D(HE)ater attack. The client requires few CPU resources and network bandwidth. The attack may be more disruptive in cases where a client can require a server to select its largest supported key size. The basic attack scenario is that the client must claim that it can only communicate with DHE, and the server must be configured to allow DHE.  

CVE-2002-20001 has been assigned to this vulnerability. A CVSS v3 base score of 7.5 has been calculated; the CVSS vector string is (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H). 

3.2.2 CLASSIC BUFFER OVERFLOW CWE-120

A buffer overflow vulnerability in an underlying service could lead to unauthenticated remote code execution by sending specially crafted packets destined to the PAPI UDP port (8211). 

CVE-2022-37885 has been assigned to this vulnerability. A CVSS v3 base score of 9.8 has been calculated; the CVSS vector string is (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

3.2.3 CLASSIC BUFFER OVERFLOW CWE-120 

A buffer overflow vulnerability in an underlying service could lead to unauthenticated remote code execution by sending specially crafted packets destined to the PAPI UDP port (8211). 

CVE-2022-37886 has been assigned to this vulnerability. A CVSS v3 base score of 9.8 has been calculated; the CVSS vector string is (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

3.2.4 CLASSIC BUFFER OVERFLOW CWE-120

A buffer overflow vulnerability in an underlying service could lead to unauthenticated remote code execution by sending specially crafted packets destined to the PAPI UDP port (8211).  

CVE-2022-37887 has been assigned to this vulnerability. A CVSS v3 base score of 9.8 has been calculated; the CVSS vector string is (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

3.2.5 CLASSIC BUFFER OVERFLOW CWE-120 

A buffer overflow vulnerability in an underlying service could lead to unauthenticated remote code execution by sending specially crafted packets destined to the PAPI UDP port (8211). 

CVE-2022-37888 has been assigned to this vulnerability. A CVSS v3 base score of 9.8 has been calculated; the CVSS vector string is (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

3.2.6 CLASSIC BUFFER OVERFLOW CWE-120

A buffer overflow vulnerability in an underlying service could lead to unauthenticated remote code execution by sending specially crafted packets destined to the PAPI UDP port (8211). 

CVE-2022-37889 has been assigned to this vulnerability. A CVSS v3 base score of 9.8 has been calculated; the CVSS vector string is (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

3.2.7 CLASSIC BUFFER OVERFLOW CWE-120

An unauthenticated buffer overflow vulnerability exists within the web management interface. Successful exploitation could result in the execution of arbitrary commands on the underlying operating system. 

CVE-2022-37890 has been assigned to this vulnerability. A CVSS v3 base score of 9.8 has been calculated; the CVSS vector string is (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

3.2.8 CLASSIC BUFFER OVERFLOW CWE-120

An unauthenticated buffer overflow vulnerability exists within the web management interface. Successful exploitation could result in the execution of arbitrary commands on the underlying operating system.  

CVE-2022-37891 has been assigned to this vulnerability. A CVSS v3 base score of 9.8 has been calculated; the CVSS vector string is (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

3.2.9 CROSS-SITE SCRIPTING CWE-79

A vulnerability in the web management interface could allow an unauthenticated remote attacker to conduct a stored cross-site scripting (XSS) attack against a user of the interface. A successful exploit could allow an attacker to execute arbitrary script code in a victim’s browser in the context of the affected interface. 

CVE-2022-37892 has been assigned to this vulnerability. A CVSS v3 base score of 5.4 has been calculated; the CVSS vector string is (CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N).

3.2.10 CROSS-SITE SCRIPTING CWE-79

A vulnerability in the web management interface could allow a remote attacker to conduct a reflected cross-site scripting (XSS) attack against a user of the interface. A successful exploit could allow an attacker to execute arbitrary script code in a victim’s browser in the context of the affected interface. 

CVE-2022-37896 has been assigned to this vulnerability. A CVSS v3 base score of 6.1 has been calculated; the CVSS vector string is (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N).

3.2.11 COMMAND INJECTION CWE-77

An authenticated command injection vulnerability exists in the command line interface. Successful exploitation of this vulnerability could result in the ability to execute arbitrary commands as a privileged user on the underlying operating system.  

CVE-2022-37893 has been assigned to this vulnerability. A CVSS v3 base score of 7.8 has been calculated; the CVSS vector string is (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H).

3.2.12 IMPROPER INPUT VALIDATION CWE-20

An unauthenticated denial of service (DoS) vulnerability exists in the handling of certain SSID strings. Successful exploitation of this vulnerability could result in the ability to interrupt the normal operation of the affected Access Point. 

CVE-2022-37894 has been assigned to this vulnerability. A CVSS v3 base score of 6.5 has been calculated; the CVSS vector string is (CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

3.2.13 IMPROPER INPUT VALIDATION CWE-20

An authenticated denial of service (DoS) vulnerability exists in the web management interface. Successful exploitation of this vulnerability could result in the ability to interrupt the normal operation of the affected Access Point.  

CVE-2022-37895 has been assigned to this vulnerability. A CVSS v3 base score of 4.9 has been calculated; the CVSS vector string is (CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H).

3.3 BACKGROUND

• CRITICAL INFRASTRUCTURE SECTORS: Multiple Sectors 
• COUNTRIES/AREAS DEPLOYED: Worldwide 
• COMPANY HEADQUARTERS LOCATION: Germany 

3.4 RESEARCHER

Siemens reported these vulnerabilities to CISA. 

4. MITIGATIONS

Siemens identified the following specific workarounds and mitigations to reduce risk: 

• CVE-2022-37885, CVE-2022-37886, CVE-2022-37887, CVE-2022-37888, and CVE-2022-37889: Enable CPSec via the cluster-security command. 
• CVE-2022-37890, CVE-2022-37891, CVE-2022-37892, CVE-2022-37895, and CVE-2022-37896: Restrict the web-based management interface to a dedicated layer 2 segment/VLAN and/or control the interface by firewall policies at layer 3 and above. 
• CVE-2022-37893: Restrict the command line interface to a dedicated layer 2 segment/VLAN and/or control the interface by firewall policies at layer 3 and above. 

As a general security measure, Siemens recommends protecting network access to devices with appropriate mechanisms. In order to operate the devices in a protected IT environment, Siemens recommends configuring the environment according to Siemens' operational guidelines for industrial security and following the recommendations in the product manuals. 

Additional information on Industrial Security by Siemens can be found at the Siemens website.

For more information, see the associated Siemens security advisory SSA-506569 in HTML and CSAF. 

Siemens SCALANCE W1750D is a brand-labeled device from Aruba. For more information regarding these vulnerabilities, see the Aruba security advisory ARUBA-PSA-2022-014. 

CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability these vulnerabilities. Specifically, users should:

• Minimize network exposure for all control system devices and/or systems, and ensure they are not accessible from the Internet.
• Locate control system networks and remote devices behind firewalls and isolate them from business networks.
• When remote access is required, use secure methods, such as Virtual Private Networks (VPNs), recognizing VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize VPN is only as secure as its connected devices.

CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.

CISA also provides a section for control systems security recommended practices on the ICS webpage at cisa.gov/ics. Several CISA products detailing cyber defense best practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.

Additional mitigation guidance and recommended practices are publicly available on the ICS webpage at cisa.gov/ics in the technical information paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies.

Organizations observing suspected malicious activity should follow established internal procedures and report findings to CISA for tracking and correlation against other incidents.

CISA also recommends users take the following measures to protect themselves from social engineering attacks: 

Do not click web links or open attachments in unsolicited email messages. 

Refer to Recognizing and Avoiding Email Scams for more information on avoiding email scams. 

Refer to Avoiding Social Engineering and Phishing Attacks for more information on social engineering attacks. 

No known public exploits specifically target these vulnerabilities. These vulnerabilities are exploitable remotely. These vulnerabilities have a low attack complexity. 

• Siemens