CVE-2021-40365

Affected devices don't process correctly certain special crafted packets sent to port 102/tcp, which could allow an attacker to cause a denial of service in the device.

Published: 2022-12-13 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-40365 is rated Moderate Risk (49.5/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.87%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-40365

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.22% 0.87% +0.66%
2 2025-12-18 0.25% 0.22% -0.04%
3 2025-12-17 — 0.25% —

Full EPSS history (11 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-40365

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2021-40365

Affected software / configurations for CVE-2021-40365

Vendor Product Version Raw CPE
siemens simatic_s7-plcsim_advanced_firmware < 5.0 cpe:2.3:o:siemens:simatic_s7-plcsim_advanced_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1200_cpu_1211c_firmware < 4.6.0 cpe:2.3:o:siemens:simatic_s7-1200_cpu_1211c_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1200_cpu_1212c_firmware < 4.6.0 cpe:2.3:o:siemens:simatic_s7-1200_cpu_1212c_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1200_cpu_1212fc_firmware < 4.6.0 cpe:2.3:o:siemens:simatic_s7-1200_cpu_1212fc_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1200_cpu_1214_fc_firmware < 4.6.0 cpe:2.3:o:siemens:simatic_s7-1200_cpu_1214_fc_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1200_cpu_1214c_firmware < 4.6.0 cpe:2.3:o:siemens:simatic_s7-1200_cpu_1214c_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1200_cpu_1214fc_firmware < 4.6.0 cpe:2.3:o:siemens:simatic_s7-1200_cpu_1214fc_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1200_cpu_1215_fc_firmware < 4.6.0 cpe:2.3:o:siemens:simatic_s7-1200_cpu_1215_fc_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1200_cpu_1215c_firmware < 4.6.0 cpe:2.3:o:siemens:simatic_s7-1200_cpu_1215c_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1200_cpu_1215fc_firmware < 4.6.0 cpe:2.3:o:siemens:simatic_s7-1200_cpu_1215fc_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1200_cpu_1217c_firmware < 4.6.0 cpe:2.3:o:siemens:simatic_s7-1200_cpu_1217c_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1200_cpu_12_1211c_firmware < 4.6.0 cpe:2.3:o:siemens:simatic_s7-1200_cpu_12_1211c_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1200_cpu_12_1212c_firmware < 4.6.0 cpe:2.3:o:siemens:simatic_s7-1200_cpu_12_1212c_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1200_cpu_12_1212fc_firmware < 4.6.0 cpe:2.3:o:siemens:simatic_s7-1200_cpu_12_1212fc_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1200_cpu_12_1214c_firmware < 4.6.0 cpe:2.3:o:siemens:simatic_s7-1200_cpu_12_1214c_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1200_cpu_12_1214fc_firmware < 4.6.0 cpe:2.3:o:siemens:simatic_s7-1200_cpu_12_1214fc_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1200_cpu_12_1215c_firmware < 4.6.0 cpe:2.3:o:siemens:simatic_s7-1200_cpu_12_1215c_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1200_cpu_12_1215fc_firmware < 4.6.0 cpe:2.3:o:siemens:simatic_s7-1200_cpu_12_1215fc_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1200_cpu_12_1217c_firmware < 4.6.0 cpe:2.3:o:siemens:simatic_s7-1200_cpu_12_1217c_firmware:*:*:*:*:*:*:*:*
siemens siplus_s7-1200_cp_1243-1_rail_firmware < 4.6.0 cpe:2.3:o:siemens:siplus_s7-1200_cp_1243-1_rail_firmware:*:*:*:*:*:*:*:*
siemens siplus_s7-1200_cp_1243-1_firmware < 4.6.0 cpe:2.3:o:siemens:siplus_s7-1200_cp_1243-1_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1507s_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1507s_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1507s_f_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1507s_f_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1508s_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1508s_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1508s_f_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1508s_f_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1510sp_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1510sp_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1510sp-1_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1510sp-1_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1511-1_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1511-1_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1511-1_pn_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1511-1_pn_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1511c_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1511c_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1511c-1_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1511c-1_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1511f-1_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1511f-1_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1511f-1_pn_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1511f-1_pn_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1511t-1_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1511t-1_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1511tf-1_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1511tf-1_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1512c_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1512c_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1512c-1_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1512c-1_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1512sp-1_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1512sp-1_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1512spf-1_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1512spf-1_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1513-1_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1513-1_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1513-1_pn_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1513-1_pn_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1513f-1_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1513f-1_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1513f-1_pn_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1513f-1_pn_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1513r-1_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1513r-1_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1515-2_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1515-2_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1515-2_pn_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1515-2_pn_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_151511c-1_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_151511c-1_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_151511f-1_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_151511f-1_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1515f-2_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1515f-2_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1515f-2_pn_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1515f-2_pn_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1515r-2_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1515r-2_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1515t-2_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1515t-2_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1515tf-2_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1515tf-2_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1516-3_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1516-3_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1516-3_dp_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1516-3_dp_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1516-3_pn_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1516-3_pn_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1516-3_pn\/dp_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1516-3_pn\/dp_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1516f-3_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1516f-3_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1516f-3_pn\/dp_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1516f-3_pn\/dp_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1516pro-2_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1516pro-2_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1516pro_f_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1516pro_f_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1516t-3_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1516t-3_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1516tf-3_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1516tf-3_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1517-3_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1517-3_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1517-3_dp_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1517-3_dp_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1517-3_pn_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1517-3_pn_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1517-3_pn\/dp_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1517-3_pn\/dp_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1517f-3_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1517f-3_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1517f-3_pn\/dp_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1517f-3_pn\/dp_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1517tf-3_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1517tf-3_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1518_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1518_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1518-4_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1518-4_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1518-4_dp_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1518-4_dp_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1518-4_pn_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1518-4_pn_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1518-4_pn\/dp_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1518-4_pn\/dp_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1518-4_pn\/dp_mfp_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1518-4_pn\/dp_mfp_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1518f-4_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1518f-4_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1518f-4_pn\/dp_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1518f-4_pn\/dp_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1518hf-4_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1518hf-4_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1518t-4_firmware < 3.0.1 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1518t-4_firmware:*:*:*:*:*:*:*:*

References for CVE-2021-40365

cvelogic Threat Intelligence