An issue was discovered in Siemens ETA4 firmware (all versions prior to Revision 08) of the SM-2558 extension module for: SICAM AK, SICAM TM 1703, SICAM BC 1703, and SICAM AK 3. Specially crafted packets sent to Port 2404/TCP could cause the affected device to go into defect mode. A cold start might be required to recover the system, a Denial-of-Service Vulnerability.