SSA-113131 V1.5 (Last Update: 2023-05-09): Denial of Service Vulnerabilities in SIMATIC S7-400 CPUs


The vulnerability classification has been performed by using the CVSS scoring system in version 3.1 (CVSS v3.1) ( The CVSS environmental score is specific to the customer’s environment and will impact the overall CVSS score. The environmental score should therefore be individually defined by the customer to accomplish final scoring.

An additional classification has been performed using the CWE classification, a community-developed list of common software security weaknesses. This serves as a common language and as a baseline for weakness identification, mitigation, and prevention efforts. A detailed list of CWE classes can be found at:

Vulnerability CVE-2018-16556

Specially crafted packets sent to port 102/tcp via Ethernet interface, via PROFIBUS, or via Multi Point Interfaces (MPI) could cause the affected devices to go into defect mode. Manual reboot is required to resume normal operation.

Successful exploitation requires an attacker to be able to send specially crafted packets to port 102/tcp via Ethernet interface, via PROFIBUS or Multi Point Interfaces (MPI). No user interaction and no user privileges are required to exploit the security vulnerability. The vulnerability could allow causing a denial of service condition of the core functionality of the CPU, compromising the availability of the system.

CVSS v3.1 Base Score 7.5 CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:C CWE CWE-20: Improper Input Validation Vulnerability CVE-2018-16557

Sending of specially crafted

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