ICS Advisory (ICSA-21-103-11)

Siemens TIM 4R-IE Devices

Click to Tweet.
Click to send to Facebook.
Click to Share.

Legal Notice

All information products included in https://us-cert.cisa.gov/ics are provided "as is" for informational purposes only. The Department of Homeland Security (DHS) does not provide any warranties of any kind regarding any information contained within. DHS does not endorse any commercial product or service, referenced in this product or otherwise. Further dissemination of this product is governed by the Traffic Light Protocol (TLP) marking in the header. For more information about TLP, see https://us-cert.cisa.gov/tlp/.


 

1. EXECUTIVE SUMMARY

  • CVSS v3 9.8
  • ATTENTION: Exploitable remotely/low attack complexity
  • Vendor: Siemens
  • Equipment: TIM 4R-IE
  • Vulnerabilities: Incorrect Type Conversion or Cast, Improper Input Validation, Improper Authentication, Security Features, Null Pointer Dereference, Data Processing Errors, Exposure of Sensitive Information to an Unauthorized Actor, Race Condition

2. RISK EVALUATION

Successful exploitation of these vulnerabilities could compromise the confidentiality, integrity, and availability of the device.

3. TECHNICAL DETAILS

    3.1 AFFECTED PRODUCTS

    The following Siemens products TIM 4R-IE communication modules are affected:

    • TIM 4R-IE (incl. SIPLUS NET variants): All versions
    • TIM 4R-IE DNP3 (incl. SIPLUS NET variants): All versions

    3.2 VULNERABILITY OVERVIEW

    3.2.1    INCORRECT TYPE CONVERSION OR CAST CWE-704

    The ULOGTOD function in ntp.d in SNTP before 4.2.7p366 does not properly perform type conversions from a precision value to a double, which allows remote attackers to cause a denial of service (infinite loop) via a crafted NTP packet.

    CVE-2015-5219 has been assigned to this vulnerability. A CVSS v3 base score of 7.5 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

    3.2.2    IMPROPER INPUT VALIDATION CWE-20

    The decodenetnum function in ntpd in NTP 4.2.x before 4.2.8p4 and 4.3.x before 4.3.77 allows remote attackers to cause a denial of service (assertion failure) via a 6 or mode 7 packet containing a long data value.

    CVE-2015-7855 has been assigned to this vulnerability. A CVSS v3 base score of 6.5 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H).

    3.2.3    IMPROPER AUTHENTICATION CWE-287

    Crypto-NAK packets in ntpd in NTP 4.2.x before 4.2.8p4 and 4.3.x before 4.3.77 allows remote attackers to bypass authentication. 

    CVE-2015-7871 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).

    3.2.4    SECURITY FEATURES CWE-254

    NTP before 4.2.8p6 and 4.3.x before 4.3.90, when configured in broadcast mode, allows man-in-the-middle attackers to conduct replay attacks by sniffing the network.

    CVE-2015-7973 has been assigned to this vulnerability. A CVSS v3 base score of 6.5 has been calculated; the CVSS vector string is (AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H).

    3.2.5    IMPROPER AUTHENTICATION CWE-287

    NTP 4.x before 4.2.8p6 and 4.3.x before 4.3.90 do not verify peer associations of symmetric keys when authenticating packets, which might allow remote attackers to conduct impersonation attacks via an arbitrary trusted key, aka a “skeleton key.”

    CVE-2015-7974 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:N/I:H/A:N).

    3.2.6    NULL POINTER DEREFERENCE CWE-476

    ntpd in NTP before 4.2.8p6 and 4.3.x before 4.3.90 allows remote attackers to cause a denial of service (NULL pointer dereference) via a ntpdc reslist command.

    CVE-2015-7977 has been assigned to this vulnerability. A CVSS v3 base score of 5.9 has been calculated; the CVSS vector string is (AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H).

    3.2.7    DATA PROCESSING ERRORS CWE-19

    NTP before 4.2.8p6 and 4.3.x before 4.3.90 allows remote attackers to cause a denial of service (client-server association tear down) by sending broadcast packets with invalid authentication to a broadcast client.

    CVE-2015-7979 has been assigned to this vulnerability. A CVSS v3 base score of 7.5 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

    3.2.8    IMPROPER INPUT VALIDATION CWE-20

    The rate limiting feature in NTP 4.x before 4.2.8p4 and 4.3.x before 4.3.77 allows remote attackers to have unspecified impact via a large number of crafted requests.

    CVE-2015-7705 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).

    3.2.9    IMPROPER INPUT VALIDATION CWE-20

    NTP before 4.2.8p6 and 4.3.x before 4.3.90 allows remote attackers to bypass the origin timestamp validation via a packet with an origin timestamp set to zero.

    CVE-2015-8138 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:N/I:L/A:N).

    3.2.10    IMPROPER INPUT VALIDATION CWE-20

    An off-path attacker can cause a preemptible client association to be demobilized in NTP 4.2.8p4 and earlier and NTPSec a5fb34b9cc89b92a8fef2f459004865c93bb7f92 by sending a crypto NAK packet to a victim client with a spoofed source address of an existing associated peer. This is true even if authentication is enabled.

    CVE-2016-1547 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:N/I:N/A:L).

    3.2.11    DATA PROCESSING ERRORS CWE-19

    An attacker can spoof a packet from a legitimate ntpd server with an origin timestamp that matches the peer->dst timestamp recorded for that server. After making this switch, the client in NTP 4.2.8p4 and earlier and NTPSec aa48d001683e5b791a743ec9c575aaf7d867a2b0c will reject all future legitimate server responses. It is possible to force the victim client to move time after the mode has been changed. ntpq gives no indication that the mode has been switched.

    CVE-2016-1548 has been assigned to this vulnerability. A CVSS v3 base score of 7.2 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:L).

    3.2.12    EXPOSURE OF SENSITIVE INFORMATION TO AN UNAUTHORIZED ACTOR CWE-200

    An exploitable vulnerability exists in the message authentication functionality of libntp in ntp 4.2.8p4 and NTPSec a5fb34b9cc89b92a8fef2f459004865c93bb7f92. An attacker can send a series of crafted messages to attempt to recover the message digest key.

    CVE-2016-1550 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).

    3.2.13    IMPROPER AUTHENTICATION CWE-287

    ntpd in NTP 4.x before 4.2.8p8 allows remote attackers to cause a denial of service (ephemeralassociation demobilization) by sending a spoofed crypto-NAK packet with incorrect authentication data at a certain time.

    CVE-2016-4953 has been assigned to this vulnerability. A CVSS v3 base score of 7.5 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

    3.2.14    CONCURRENT EXECUTION USING SHARED RESOURCE WITH IMPROPER SYNCHRONIZATION ('RACE CONDITION')CWE-362

    The process_packet function in ntp_proto.c in ntpd in NTP 4.x before 4.2.8p8 allows remote attackers to cause a denial of service (peer-variable modification) by sending spoofed packets from many source IP addresses in a certain scenario, as demonstrated by triggering an incorrect leap indication.

    CVE-2016-4954 has been assigned to this vulnerability. A CVSS v3 base score of 7.5 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

    3.3 BACKGROUND

    • CRITICAL INFRASTRUCTURE SECTORS: Critical Manufacturing
    • COUNTRIES/AREAS DEPLOYED: Worldwide
    • COMPANY HEADQUARTERS LOCATION: Germany

    3.4 RESEARCHER

    Siemens reported these vulnerabilities to CISA.

    4. MITIGATIONS

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

    • Deactivate NTP-based time synchronization of the device, if enabled. The feature is disabled by default.
    • Configure an additional firewall to prevent communication to the Port UDP/123 of an affected device.
    • Migrate to a successor product.

    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 following the recommendations in the product manuals.

    For additional information, please refer to Siemens Security Advisory SSA-497656

    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 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 on us-cert.cisa.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.cisa.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.


    Contact Information

    For any questions related to this report, please contact the CISA at:

    Email: CISAservicedesk@cisa.dhs.gov
    Toll Free: 1-888-282-0870

    For industrial control systems cybersecurity information:  https://us-cert.cisa.gov/ics 
    or incident reporting:  https://us-cert.cisa.gov/report

    CISA continuously strives to improve its products and services. You can help by choosing one of the links below to provide feedback about this product.

    This product is provided subject to this Notification and this Privacy & Use policy.

    Please share your thoughts.

    We recently updated our anonymous product survey; we'd welcome your feedback.