CVE-2021-31345

A vulnerability has been identified in Capital Embedded AR Classic 431-422 (All versions), Capital Embedded AR Classic R20-11 (All versions < V2303), PLUSCONTROL 1st Gen (All versions). The total length of an UDP payload (set in the IP header) is unchecked. This may lead to various side effects, including Information Leak and Denial-of-Service conditions, depending on a user-defined applications that runs on top of the UDP protocol. (FSMD-2021-0006)

Published: 2021-11-09 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-31345 is rated Moderate Risk (55.6/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.58%). 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-2021-31345

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 1.25% 1.58% +0.33%
2 2025-07-08 0.87% 1.25% +0.38%
3 2025-06-09 — 0.87% —

Full EPSS history (17 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-31345

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:H/I:N/A:N 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:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 3.6 [email protected]
9.1 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/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:H)
Serious risk that confidential data gets exposed in a big 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 5.2 [email protected]
6.4 2.0 MEDIUM
AV:N/AC:L/Au:N/C:P/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 4.9 [email protected]

Weakness enumeration for CVE-2021-31345

Affected software / configurations for CVE-2021-31345

Vendor Product Version Raw CPE
siemens capital_vstar — cpe:2.3:a:siemens:capital_vstar:*:*:*:*:*:*:*:*
siemens nucleus_net — cpe:2.3:a:siemens:nucleus_net:*:*:*:*:*:*:*:*
siemens nucleus_readystart_v3 < 2014.12 cpe:2.3:a:siemens:nucleus_readystart_v3:*:*:*:*:*:*:*:*
siemens nucleus_source_code — cpe:2.3:a:siemens:nucleus_source_code:*:*:*:*:*:*:*:*
siemens apogee_modular_building_controller_firmware — cpe:2.3:o:siemens:apogee_modular_building_controller_firmware:*:*:*:*:*:*:*:*
siemens apogee_modular_equiment_controller_firmware — cpe:2.3:o:siemens:apogee_modular_equiment_controller_firmware:*:*:*:*:*:*:*:*
siemens apogee_pxc_compact_firmware — cpe:2.3:o:siemens:apogee_pxc_compact_firmware:*:*:*:*:*:*:*:*
siemens apogee_pxc_modular_firmware — cpe:2.3:o:siemens:apogee_pxc_modular_firmware:*:*:*:*:*:*:*:*
siemens talon_tc_compact_firmware — cpe:2.3:o:siemens:talon_tc_compact_firmware:*:*:*:*:*:*:*:*
siemens talon_tc_modular_firmware — cpe:2.3:o:siemens:talon_tc_modular_firmware:*:*:*:*:*:*:*:*

References for CVE-2021-31345

cvelogic Threat Intelligence