CVE-2025-40820
No fix known EPSS <1%CVSS 7.5
Affected products do not properly enforce TCP sequence number validation in specific scenarios but accept values within a broad range. This could allow an unauthenticated remote attacker e.g. to interfere with connection setup, potentially leading to a denial of service. The attack succeeds only if an attacker can inject IP packets with spoofed addresses at precisely timed moments, and it affects only TCP-based services.
Products: Siemens SIDOOR ATD430W, Siemens SIDOOR ATE530G COATED, Siemens SIDOOR ATE530S COATED, Siemens SIMATIC CFU DIQ, Siemens SIMATIC CFU PA, Siemens SIMATIC ET 200AL IM 157-1 PN, Siemens SIMATIC ET 200clean, CM 8x IO-Link, Siemens SIMATIC ET 200clean, DI 16x24VDC, Siemens SIMATIC ET 200clean, DIQ 16x24VDC/0,5A, Siemens SIMATIC ET 200eco PN, AI 8xRTD/TC, M12-L, Siemens SIMATIC ET 200eco PN, CM 4x IO-Link, M12-L, Siemens SIMATIC ET 200eco PN, CM 8x IO-Link, M12-L, Siemens SIMATIC ET 200eco PN, DI 16x24VDC, M12-L, Siemens SIMATIC ET 200eco PN, DI 8x24VDC, M12-L, Siemens SIMATIC ET 200eco PN, DIQ 16x24VDC/2A, M12-L, Siemens SIMATIC ET 200eco PN, DQ 8x24VDC/0,5A, M12-L, Siemens SIMATIC ET 200eco PN, DQ 8x24VDC/2A, M12-L, Siemens SIMATIC ET 200MP IM 155-5 PN HF, Siemens SIMATIC ET 200pro IM 154-8 PN/DP CPU, Siemens SIMATIC ET 200pro IM 154-8F PN/DP CPU, Siemens SIMATIC ET 200pro IM 154-8FX PN/DP CPU, Siemens SIMATIC ET 200S IM 151-8 PN/DP CPU, Siemens SIMATIC ET 200S IM 151-8F PN/DP CPU, Siemens SIMATIC ET 200SP CPU 1510SP F-1 PN, Siemens SIMATIC ET 200SP CPU 1510SP-1 PN, Siemens SIMATIC ET 200SP CPU 1512SP F-1 PN, Siemens SIMATIC ET 200SP CPU 1512SP-1 PN, Siemens SIMATIC ET 200SP IM 155-6 MF HF, Siemens SIMATIC ET 200SP IM 155-6 PN HA (incl. SIPLUS variants), Siemens SIMATIC ET 200SP IM 155-6 PN HF, Siemens SIMATIC ET 200SP IM 155-6 PN/2 HF, Siemens SIMATIC ET 200SP IM 155-6 PN/3 HF, Siemens SIMATIC PN/MF Coupler, Siemens SIMATIC PN/PN Coupler, Siemens SIMATIC Power Line Booster PLB, Base Module, Siemens SIMATIC Power Line Booster PLB, Modem Module ST, Siemens SIMATIC S7-1200 CPU 1211C AC/DC/Rly, Siemens SIMATIC S7-1200 CPU 1211C DC/DC/DC, Siemens SIMATIC S7-1200 CPU 1211C DC/DC/Rly, Siemens SIMATIC S7-1200 CPU 1212C AC/DC/Rly, Siemens SIMATIC S7-1200 CPU 1212C DC/DC/DC, Siemens SIMATIC S7-1200 CPU 1212C DC/DC/Rly, Siemens SIMATIC S7-1200 CPU 1212FC DC/DC/DC, Siemens SIMATIC S7-1200 CPU 1212FC DC/DC/Rly, Siemens SIMATIC S7-1200 CPU 1214C AC/DC/Rly, Siemens SIMATIC S7-1200 CPU 1214C DC/DC/DC, Siemens SIMATIC S7-1200 CPU 1214C DC/DC/Rly, Siemens SIMATIC S7-1200 CPU 1214FC DC/DC/DC, Siemens SIMATIC S7-1200 CPU 1214FC DC/DC/Rly, Siemens SIMATIC S7-1200 CPU 1215C AC/DC/Rly, Siemens SIMATIC S7-1200 CPU 1215C DC/DC/DC, Siemens SIMATIC S7-1200 CPU 1215C DC/DC/Rly, Siemens SIMATIC S7-1200 CPU 1215FC DC/DC/DC, Siemens SIMATIC S7-1200 CPU 1215FC DC/DC/Rly, Siemens SIMATIC S7-1200 CPU 1217C DC/DC/DC, Siemens SIMATIC S7-1500 CPU 1511-1 PN, Siemens SIMATIC S7-1500 CPU 1511F-1 PN, Siemens SIMATIC S7-1500 CPU 1513-1 PN, Siemens SIMATIC S7-1500 CPU 1513F-1 PN, Siemens SIMATIC S7-1500 CPU 1515-2 PN, Siemens SIMATIC S7-1500 CPU 1515F-2 PN, Siemens SIMATIC S7-1500 CPU 1516-3 PN/DP, Siemens SIMATIC S7-1500 CPU 1516F-3 PN/DP, Siemens SIMATIC S7-200 SMART CPU CR40, Siemens SIMATIC S7-200 SMART CPU CR60, Siemens SIMATIC S7-200 SMART CPU SR20, Siemens SIMATIC S7-200 SMART CPU SR30, Siemens SIMATIC S7-200 SMART CPU SR40, Siemens SIMATIC S7-200 SMART CPU SR60, Siemens SIMATIC S7-200 SMART CPU ST20, Siemens SIMATIC S7-200 SMART CPU ST30, Siemens SIMATIC S7-200 SMART CPU ST40, Siemens SIMATIC S7-200 SMART CPU ST60, Siemens SIMATIC S7-300 CPU 314C-2 PN/DP, Siemens SIMATIC S7-300 CPU 315-2 PN/DP, Siemens SIMATIC S7-300 CPU 315F-2 PN/DP, Siemens SIMATIC S7-300 CPU 315T-3 PN/DP, Siemens SIMATIC S7-300 CPU 317-2 PN/DP, Siemens SIMATIC S7-300 CPU 317F-2 PN/DP, Siemens SIMATIC S7-300 CPU 317T-3 PN/DP, Siemens SIMATIC S7-300 CPU 317TF-3 PN/DP, Siemens SIMATIC S7-300 CPU 319-3 PN/DP, Siemens SIMATIC S7-300 CPU 319F-3 PN/DP, Siemens SIMATIC S7-400 CPU 412-2 PN V7, Siemens SIMATIC S7-400 CPU 414-3 PN/DP V7, Siemens SIMATIC S7-400 CPU 414F-3 PN/DP V7, Siemens SIMATIC S7-400 CPU 416-3 PN/DP V7, Siemens SIMATIC S7-400 CPU 416F-3 PN/DP V7, Siemens SIMATIC S7-400 H V6 CPU family (incl. SIPLUS variants), Siemens SIMATIC S7-410 V10 CPU family (incl. SIPLUS variants), Siemens SIMATIC S7-410 V8 CPU family (incl. SIPLUS variants), Siemens SIMATIC TDC CP51M1, Siemens SIMATIC TDC CPU555, Siemens SIMOCODE pro V Ethernet/IP (incl. SIPLUS variants), Siemens SIMOCODE pro V PROFINET, Siemens SINUMERIK 840D sl, Siemens SIPLUS ET 200MP IM 155-5 PN HF, Siemens SIPLUS ET 200MP IM 155-5 PN HF T1 RAIL, Siemens SIPLUS ET 200S IM 151-8 PN/DP CPU, Siemens SIPLUS ET 200S IM 151-8F PN/DP CPU, Siemens SIPLUS ET 200SP CPU 1512SP F-1 PN, Siemens SIPLUS ET 200SP IM 155-6 PN HF, Siemens SIPLUS ET 200SP IM 155-6 PN HF T1 RAIL, Siemens SIPLUS ET 200SP IM 155-6 PN HF TX RAIL, Siemens SIPLUS HCS4200 CIM4210, Siemens SIPLUS HCS4200 CIM4210C, Siemens SIPLUS HCS4300 CIM4310, Siemens SIPLUS NET PN/PN Coupler, Siemens SIPLUS S7-1200 CPU 1212 AC/DC/RLY, Siemens SIPLUS S7-1200 CPU 1212 DC/DC/RLY, Siemens SIPLUS S7-1200 CPU 1212C AC/DC/RLY, Siemens SIPLUS S7-1200 CPU 1212C DC/DC/DC, Siemens SIPLUS S7-1200 CPU 1212C DC/DC/DC RAIL, Siemens SIPLUS S7-1200 CPU 1214 AC/DC/RLY, Siemens SIPLUS S7-1200 CPU 1214 DC/DC/RLY, Siemens SIPLUS S7-1200 CPU 1214C AC/DC/RLY, Siemens SIPLUS S7-1200 CPU 1214C DC/DC/DC, Siemens SIPLUS S7-1200 CPU 1214C DC/DC/DC RAIL, Siemens SIPLUS S7-1200 CPU 1214C DC/DC/RLY, Siemens SIPLUS S7-1200 CPU 1214FC DC/DC/DC, Siemens SIPLUS S7-1200 CPU 1214FC DC/DC/RLY, Siemens SIPLUS S7-1200 CPU 1215 AC/DC/RLY, Siemens SIPLUS S7-1200 CPU 1215 DC/DC/DC, Siemens SIPLUS S7-1200 CPU 1215 DC/DC/RLY, Siemens SIPLUS S7-1200 CPU 1215C AC/DC/RLY, Siemens SIPLUS S7-1200 CPU 1215C DC/DC/DC, Siemens SIPLUS S7-1200 CPU 1215FC DC/DC/DC, Siemens SIPLUS S7-1500 CPU 1511-1 PN, Siemens SIPLUS S7-1500 CPU 1511F-1 PN, Siemens SIPLUS S7-1500 CPU 1513-1 PN, Siemens SIPLUS S7-1500 CPU 1513F-1 PN, Siemens SIPLUS S7-1500 CPU 1516-3 PN/DP, Siemens SIPLUS S7-1500 CPU 1516F-3 PN/DP, Siemens SIPLUS S7-300 CPU 314C-2 PN/DP, Siemens SIPLUS S7-300 CPU 315-2 PN/DP, Siemens SIPLUS S7-300 CPU 315F-2 PN/DP, Siemens SIPLUS S7-300 CPU 317-2 PN/DP, Siemens SIPLUS S7-300 CPU 317F-2 PN/DP, Siemens SIPLUS S7-400 CPU 414-3 PN/DP V7, Siemens SIPLUS S7-400 CPU 416-3 PN/DP V7, Siemens SIWAREX WP231, Siemens SIWAREX WP241, Siemens SIWAREX WP251, Siemens SIWAREX WP521 ST, Siemens SIWAREX WP522 ST