CVE-2025-40820: Affected products do not properly enforce TCP sequence number validation in specific scenarios but accept values within a broad range. This could allow an…

PriorityP345high7.5CVSS 3.1

AVNACLPRNUINSUCNINAH

EPSS

0.42%

34.4th percentile

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.

Affected

132 ranges· showing 25

Vendor	Product	Version range	Fixed in
siemens	sidoor_atd430w	< *	*
siemens	sidoor_ate530g_coated	< *	*
siemens	sidoor_ate530s_coated	< *	*
siemens	simatic_cfu_diq	< V2.0.0	V2.0.0
siemens	simatic_cfu_pa	< V2.0.0	V2.0.0
siemens	simatic_et_200al_im_157-1_pn	< *	*
siemens	simatic_et_200mp_im_155-5_pn_hf	>= V4.2.0 < *	*
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-1_pn	< *	*
siemens	simatic_et_200sp_cpu_1510sp_f-1_pn	< *	*
siemens	simatic_et_200sp_cpu_1512sp-1_pn	< *	*
siemens	simatic_et_200sp_cpu_1512sp_f-1_pn	< *	*
siemens	simatic_et_200sp_im_155-6_mf_hf	< *	*
siemens	simatic_et_200sp_im_155-6_pn_2_hf	>= V4.2.0 < *	*
siemens	simatic_et_200sp_im_155-6_pn_3_hf	>= V4.2.0 < *	*
siemens	simatic_et_200sp_im_155-6_pn_ha	< V1.3	V1.3
siemens	simatic_et_200sp_im_155-6_pn_hf	>= V4.2.0 < *	*
siemens	simatic_pn_mf_coupler	< *	*
siemens	simatic_pn_pn_coupler	< V6.0.0	V6.0.0
siemens	simatic_s7-1200_cpu_1211c_ac_dc_rly	< V4.4.0	V4.4.0
siemens	simatic_s7-1200_cpu_1211c_dc_dc_dc	< V4.4.0	V4.4.0

CVSS provenance

nvdv3.17.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

nvdv4.08.7HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

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