CVE-2021-22708Public exploitNetwork attack vector

Remote code execution via forged firmware package

Published Jul 21, 2021 · Updated Aug 3, 2024

Improper cryptographic signature verification in Schneider Electric EVlink charging stations before R8 V3.4.0.1 allows remote authenticated attackers to execute code via a crafted firmware package. The epk-install.sh updater recomputes a SHA-256 value with a hard-coded secret instead of verifying a genuine digital signature, so modified contents and a matching CONTROL file are accepted. Exploitation requires authenticated access to the charging station update interface and can replace firmware, yielding code execution and loss of firmware integrity.

CVSS severity6.5
Medium
EPSS probability0.65%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper cryptographic signature verification in Schneider Electric EVlink charging stations before R8 V3.4.0.1 allows remote authenticated attackers to execute code via a crafted firmware package. The epk-install.sh updater recomputes a SHA-256 value with a hard-coded secret instead of verifying a genuine digital signature, so modified contents and a matching CONTROL file are accepted. Exploitation requires authenticated access to the charging station update interface and can replace firmware, yielding code execution and loss of firmware integrity.

The record

CVE
CVE-2021-22708
Published
Jul 21, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-347, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 21, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.5NVDAV:N/AC:L/Au:S/C:P/I:P/A:P
7.2NVDCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-347Improper Verification of Cryptographic Signature
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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