1. EXECUTIVE SUMMARY

  • CVSS v3 9.9
  • ATTENTION: Exploitable remotely/low skill level to exploit
  • Vendor: Siemens
  • Equipment: SiNVR 3
  • Vulnerabilities: Cleartext Storage of Sensitive Information in GUI, Improper Authentication, Relative Path Traversal, Missing Authentication for Critical Function, Weak Cryptography for Passwords, Exposed Dangerous Method or Function

2. RISK EVALUATION

Successful exploitation of these vulnerabilities could allow an attacker to read (and reset) passwords of other SiNVR 3 CCS (Central Control Server) users, read the CCS and SiNVR users database including the passwords of all users in obfuscated cleartext, list arbitrary directories or read files outside of the CCS application context, extract device configuration files and passwords from the user database, read data from the EDIR directory, read or delete arbitrary files, or access other resources on the same CCS server.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

The following versions of SiNVR 3, a video management solution, are affected:

  • SiNVR 3 Central Control Server (CCS): all versions
  • SiNVR 3 Video Server: all versions

3.2 VULNERABILITY OVERVIEW

3.2.1 CLEARTEXT STORAGE OF SENSITIVE INFORMATION IN GUI CWE-317

The user configuration menu in the web interface of the SiNVR 3 CCS transfers user passwords in cleartext to the client (browser).

CVE-2019-13947 has been assigned to this vulnerability. A CVSS v3 base score of 4.9 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N).

3.2.2 IMPROPER AUTHENTICATION CWE-287

The SiNVR 3 CCS contains an authentication bypass vulnerability in its XML-based communication protocol as provided by default on specific ports.

CVE-2019-18337 has been assigned to this vulnerability. A CVSS v3 base score of 9.8 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

3.2.3 RELATIVE PATH TRAVERSAL CWE-23

The SiNVR 3 CCS contains a directory traversal vulnerability in its XML-based communication protocol as provided by default on specific ports.

CVE-2019-18338 has been assigned to this vulnerability. A CVSS v3 base score of 7.7 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N).

3.2.4 MISSING AUTHENTICATION FOR CRITICAL FUNCTION CWE-306

The HTTP service (default specific port) of the SiNVR 3 Video Server contains an authentication bypass vulnerability, even when properly configured with enforced authentication.

CVE-2019-18339 has been assigned to this vulnerability. A CVSS v3 base score of 9.8 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

3.2.5 WEAK CRYPTOGRAPHY FOR PASSWORDS CWE-261

Both the SiNVR 3 Video Server and the CCS store user and device passwords by applying weak cryptography.

CVE-2019-18340 has been assigned to this vulnerability. A CVSS v3 base score of 5.5 has been calculated; the CVSS vector string is (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N).

3.2.6 IMPROPER AUTHENTICATION CWE-287

The SFTP service (default specific port) of the SiNVR 3 CCS contains an authentication bypass vulnerability.

CVE-2019-18341 has been assigned to this vulnerability. A CVSS v3 base score of 5.3 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N).

3.2.7 EXPOSED DANGEROUS METHOD OR FUNCTION CWE-749

The SFTP service (default specific port) of the SiNVR 3 CCS does not properly limit its capabilities to the specified purpose.

CVE-2019-18342 has been assigned to this vulnerability. A CVSS v3 base score of 9.9 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H).

3.3 BACKGROUND

  • CRITICAL INFRASTRUCTURE SECTORS: Commercial Facilities
  • COUNTRIES/AREAS DEPLOYED: Worldwide
  • COMPANY HEADQUARTERS LOCATION: Germany

3.4 RESEARCHER

Raphaël Rigo from Airbus Security Lab reported these vulnerabilities to Siemens.

4. MITIGATIONS

Siemens has identified the following specific workarounds and mitigations users can apply to reduce the risk:

  • General – Apply ACL/firewall configuration on the SiNVR Video and CCS servers to ensure only legitimate SiNVR systems can access the configured Video/CCS server ports. Harden all SiNVR systems accordingly to prevent unauthorized access. Consider applying encryption and authentication on the network (e.g., via TLS on application level or via IPSec on host level).
  • CVE-2019-18338, CVE-2019-18341, CVE-2019-18342: Limit the access of the CCS server application to other applications that are not part of it.
  • CVE-2019-18339: SiNVR deployments with active CCS should ensure that every SiNVR server and client has the Authorization Server set to “Control Center Server” (Configuration -> Appearance -> Desktop -> Authorization Server).
  • CVE-2019-18340: Harden the SiNVR Video servers and CCS server to prevent local access by unauthorized users.
  • CVE-2019-13947: Disable the web interface of CCS if not used. Alternatively, restrict access from localhost only, or only to trusted hosts of CCS administrators. Enable TLS for the web interface of CCS.

As a general security measure, Siemens strongly 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 to following the recommendations in the product manuals.

Additional information on industrial security by Siemens can be found at:

https://www.siemens.com/industrialsecurity

For more information on these vulnerabilities and more detailed mitigation instructions, please see Siemens security advisory SSA-761617 at the following location:

http://www.siemens.com/cert/advisories

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

  • Minimize network exposure for all control system devices and/or systems, and ensure that they are not accessible from the Internet.
  • Locate control system networks and remote devices behind firewalls, and isolate them from the business network.
  • When remote access is required, use secure methods, such as Virtual Private Networks (VPNs), recognizing that VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize that VPN is only as secure as the 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 on us-cert.gov. Several recommended 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 on us-cert.gov in the Technical Information Paper, ICS-TIP-12-146-01B–Targeted Cyber Intrusion Detection and Mitigation Strategies.

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

No known public exploits specifically target these vulnerabilities.

Source:

https://www.us-cert.gov/ics/advisories/icsa-19-344-02