CVE-2021-31605Public exploitNetwork attack vector

Server shutdown via injected management command

Published Sep 27, 2021 · Updated Aug 3, 2024

OS command injection in furlongm openvpn-monitor through 1.1.3 allows remote attackers to shut down the server via HTTP requests to the monitoring interface. URL-decoded input containing %0a is forwarded to the OpenVPN management interface socket, allowing injected commands such as signal SIGTERM to be executed. An exposed monitoring endpoint is sufficient for unauthenticated network access; the documented consequence is service interruption without reported confidentiality or integrity impact.

CVSS severity7.5
High
EPSS probability3.34%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

OS command injection in furlongm openvpn-monitor through 1.1.3 allows remote attackers to shut down the server via HTTP requests to the monitoring interface. URL-decoded input containing %0a is forwarded to the OpenVPN management interface socket, allowing injected commands such as signal SIGTERM to be executed. An exposed monitoring endpoint is sufficient for unauthenticated network access; the documented consequence is service interruption without reported confidentiality or integrity impact.

The record

CVE
CVE-2021-31605
Published
Sep 27, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-78, T1059
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 27, 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 privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.5NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.8NVDAV:N/AC:L/Au:N/C:N/I:N/A:C

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
T1059Command and Scripting Interpreter

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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