Vulnerability identifier: #VU13570
Vulnerability risk: High
CVSSv3.1: 9.1 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H/E:P/RL:U/RC:C]
CVE-ID:
CWE-ID:
CWE-264
Exploitation vector: Network
Exploit availability: No
Vulnerable software:
SICLOCK TC400
Client/Desktop applications /
Other client software
SICLOCK TC100
Client/Desktop applications /
Other client software
Vendor: Siemens
Description
Mitigation
Siemens has identified the following specific workarounds and mitigations that customers can apply to
reduce the risk:
• Provide redundant time sources and implement plausibility checks for the time information in critical
plant controllers.
• Protect network access to the affected devices with appropriate measures, e.g. protect SICLOCK
TC devices with firewalls to reduce the risk.
It is recommended to filter traffic to all ports excluding those needed for time synchronization. If
time synchronization is performed using NTP, then port 123/udp must be opened on the firewall. If
time synchronization is performed using SIMATIC time synchronization, then port 22223/udp and
port 22224/udp must be opened on the firewall.
For configuring parameters, it is recommended to use a direct connection to the SICLOCK TC.
• Apply the cell protection concept, and apply defense-in-depth: https://www.siemens.com/cert/
operational-guidelines-industrial-security
Vulnerable software versions
SICLOCK TC400: All versions
SICLOCK TC100: All versions
External links
http://cert-portal.siemens.com/productcert/pdf/ssa-197012.pdf
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.