CVE-2021-31338Public exploit

SYSTEM code execution via unauthenticated OpenVPN configuration

Published Aug 19, 2021 · Updated Aug 3, 2024

External configuration control in Siemens SINEMA Remote Connect Client before 3.0 SP1 allows local users to execute code as SYSTEM. Its privileged back-end service accepts an unauthenticated config command from any local application and launches OpenVPN with an attacker-chosen configuration. A malicious OpenVPN up directive then runs a shell command with SYSTEM privileges; a browser-delivered variant additionally requires a malicious page and reachable SMB share.

CVSS severity7.8
High
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

External configuration control in Siemens SINEMA Remote Connect Client before 3.0 SP1 allows local users to execute code as SYSTEM. Its privileged back-end service accepts an unauthenticated config command from any local application and launches OpenVPN with an attacker-chosen configuration. A malicious OpenVPN up directive then runs a shell command with SYSTEM privileges; a browser-delivered variant additionally requires a malicious page and reachable SMB share.

The record

CVE
CVE-2021-31338
Published
Aug 19, 2021
Updated
Aug 3, 2024
Vendor
Siemens
Product
SINEMA Remote Connect Client
Classifications
CWE-15, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 19, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=All versions < V3.0 SP1

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Siemens · SINEMA Remote Connect Clientversion=All versions < V3.0 SP1

Published CVSS scores

4.6NIST NVDAV:L/AC:L/Au:N/C:P/I:P/A:P
7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-15External Control of System or Configuration Setting
T1068Exploitation for Privilege Escalation

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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