Affected devices improperly handle large amounts of specially crafted UDP packets. This could allow an unauthenticated remote attacker to trigger a denial of service condition.

An attacker with network access to an affected product may cause a denial of service condition by breaking the real-time synchronization (IRT) of the affected installation.

The webserver of the affected devices contains a vulnerability that may lead to a denial of service condition. An attacker may cause a denial of service situation which leads to a restart of the webserver of the affected device. The security vulnerability could be exploited by an attacker with network access to the affected systems. Successful exploitation requires no system privileges and no user interaction. An attacker could use the vulnerability to compromise availability of the device.

Specially crafted packets sent to port 161/udp could cause a denial of service condition. The affected devices must be restarted manually.

Specially crafted PROFINET DCP packets sent on a local Ethernet segment (Layer 2) to an affected product could cause a denial of service condition of that product. Human interaction is required to recover the system. PROFIBUS interfaces are not affected.

Specially crafted PROFINET DCP broadcast packets could cause a denial of service condition of affected products on a local Ethernet segment (Layer 2). Human interaction is required to recover the systems. PROFIBUS interfaces are not affected.

Siemens SINAMICS S/G controllers with firmware before 4.6.11 do not require authentication for FTP and TELNET sessions, which allows remote attackers to bypass intended access restrictions via TCP traffic to port (1) 21 or (2) 23.