What is the CVSS score of CVE-2021-22727?

CVE-2021-22727 has a CVSS 3.1 base score of 9.8 (Critical). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 1.4%.

Evlink City Evc1S22P4 Firmware CVE-2021-22727

CRITICAL

Insufficient Entropy (CWE-331)

2021-07-21 cybersecurity@se.com

Authentication Bypass Schneider Electric Evlink City Evc1S22P4 Firmware Evlink City Evc1S7P4 Firmware Evlink Parking Evw2 Firmware Evlink Parking Evf2 Firmware Evlink Parking Ev 2 Firmware Evlink Smart Wallbox Evb1A Firmware

9.8

CVSS 3.1 · NVD

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Vulnerability Assessment

Weakness	CWE CWE-331 OWASP Top 10:2025 A04:2025 - Cryptographic Failures ASVS 5.0 V11 - Cryptography Entropy requirements
Impact	CVSS score of 9.8 (CRITICAL). Attack characteristics: network attack vector, low complexity, no privileges required, no user interaction not required.
Exploit ScenarioDerived	This vulnerability can be exploited remotely over the network. Successful exploitation could compromise the critical-severity affected system.

Act Now Prioritize within 24-48h. Why: CRITICAL severity.

No patch listed yet 1.4% exploitation probability (EPSS)

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AnalysisAI

A CWE-331: Insufficient Entropy vulnerability exists in EVlink City (EVC1S22P4 / EVC1S7P4 all versions prior to R8 V3.4.0.1), EVlink Parking (EVW2 / EVF2 / EV.2 all versions prior to R8 V3.4.0.1),. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.

Affects your stack

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Technical ContextAI · show details

This vulnerability is classified under CWE-331. A CWE-331: Insufficient Entropy vulnerability exists in EVlink City (EVC1S22P4 / EVC1S7P4 all versions prior to R8 V3.4.0.1), EVlink Parking (EVW2 / EVF2 / EV.2 all versions prior to R8 V3.4.0.1), and EVlink Smart Wallbox (EVB1A all versions prior to R8 V3.4.0.1 ) that could allow an attacker to gain unauthorized access to the charging station web server Affected products include: Schneider-Electric Evlink City Evc1S22P4 Firmware, Schneider-Electric Evlink City Evc1S7P4 Firmware, Schneider-Electric Evlink Parking Evw2 Firmware, Schneider-Electric Evlink Parking Evf2 Firmware, Schneider-Electric Evlink Parking Ev.2 Firmware.

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

NVD PRIMARY 9.8 CRITICAL

AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

DescriptionNVD

A CWE-331: Insufficient Entropy vulnerability exists in EVlink City (EVC1S22P4 / EVC1S7P4 all versions prior to R8 V3.4.0.1), EVlink Parking (EVW2 / EVF2 / EV.2 all versions prior to R8 V3.4.0.1), and EVlink Smart Wallbox (EVB1A all versions prior to R8 V3.4.0.1 ) that could allow an attacker to gain unauthorized access to the charging station web server

Threat Intelligence Overview

EPSS Score

1.4%

Top 31% exploitable

Data Quality

2 sources

Confidence: Low

NVD

CVE.org

EPSS

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue

Severity CRITICAL

CISA KEV No

Public POC No

EPSS 1.4%

Patch available No

Active threat No

Deciding rule

CRITICAL severity

What every action level means

Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.

Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.

This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.

This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.

Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived

Scheduled

Exploitation· derived

None

System Exposure· derived

Open

Automatable· derived

Yes

Human Impact· derived

Medium

Priority Score

Low Medium High Critical

KEV: 0

EPSS: +1

CVSS: +49

PoC: 0

Weaponized: 0

Threat intel: 0

Gov advisory: 0

Attack Technique

Authentication Bypass CRITICAL

Authentication bypass attacks exploit flaws in the verification mechanisms that control access to systems and applications.

Affected Products (CPE)NVD

cpe:2.3:o:schneider-electric:evlink_city_evc1s22p4_firmware:*:*:*:*:*:*:*:*

cpe:2.3:o:schneider-electric:evlink_city_evc1s7p4_firmware:*:*:*:*:*:*:*:*

cpe:2.3:o:schneider-electric:evlink_parking_evw2_firmware:*:*:*:*:*:*:*:*

cpe:2.3:o:schneider-electric:evlink_parking_evf2_firmware:*:*:*:*:*:*:*:*

cpe:2.3:o:schneider-electric:evlink_parking_ev.2_firmware:*:*:*:*:*:*:*:*

cpe:2.3:o:schneider-electric:evlink_smart_wallbox_evb1a_firmware:*:*:*:*:*:*:*:*

More in Evlink City Evc1S22P4 Firmware

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CVE-2021-22707 CRITICAL Act Now POC

9.8 Jul 21

A CWE-798: Use of Hard-coded Credentials vulnerability exists in EVlink City (EVC1S22P4 / EVC1S7P4 all versions prior to

CVE-2021-22730 CRITICAL Act Now

9.8 Jul 21

A CWE-798: Use of Hard-coded Credentials vulnerability exists in EVlink City (EVC1S22P4 / EVC1S7P4 all versions prior to

CVE-2021-22729 CRITICAL Act Now

9.8 Jul 21

A CWE-259: Use of Hard-coded Password vulnerability exists in EVlink City (EVC1S22P4 / EVC1S7P4 all versions prior to R8

CVE-2021-22726 HIGH This Week

8.1 Jul 21

A CWE-918: Server-Side Request Forgery (SSRF) vulnerability exists in EVlink City (EVC1S22P4 / EVC1S7P4 all versions pri

CVE-2021-22774 HIGH This Week

7.5 Jul 21

A CWE-759: Use of a One-Way Hash without a Salt vulnerability exists in EVlink City (EVC1S22P4 / EVC1S7P4 all versions p

CVE-2021-22708 HIGH This Week

7.2 Jul 21

A CWE-347: Improper Verification of Cryptographic Signature vulnerability exists in EVlink City (EVC1S22P4 / EVC1S7P4 al

CVE-2021-22773 MEDIUM This Month

6.5 Jul 21

A CWE-620: Unverified Password Change vulnerability exists in EVlink City (EVC1S22P4 / EVC1S7P4 all versions prior to R8

CVE-2021-22728 MEDIUM This Month

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A CWE-200: Information Exposure vulnerability exists in EVlink City (EVC1S22P4 / EVC1S7P4 all versions prior to R8 V3.4.

CVE-2021-22723 MEDIUM This Month

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A CWE-79: Improper Neutralization of Input During Web Page Generation (Cross-siteScripting) through Cross-Site Request F

CVE-2021-22706 MEDIUM This Month

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A CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability exists in E

CVE-2021-22722 MEDIUM This Month

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A CWE-79: Improper Neutralization of Input During Web Page Generation ('Stored Cross-site Scripting') vulnerability exis

CVE-2021-22721 MEDIUM This Month

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A CWE-200: Information Exposure vulnerability exists in EVlink City (EVC1S22P4 / EVC1S7P4 all versions prior to R8 V3.4.

Same weakness CWE-331 – Insufficient Entropy

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References

Advisories & patches

ADVISORY http://download.schneider-electric.com/files?p_Doc_Ref=SEVD-2021-194-06

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GitHub PoC

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