CVE-2021-22642Network attack vector

Unauthenticated crash via unchecked Modbus frame

Published Jul 28, 2022 · Updated Apr 17, 2025

Resource exhaustion in Ovarro TBox firmware 1.45 and earlier allows remote attackers to crash the RTU via malformed Modbus frames. The main RTU program assumes every received Modbus frame is valid and processes a crafted invalid packet without validation. Unauthenticated network access to the Modbus service is sufficient, and exploitation interrupts the controller's monitoring and control functions.

CVSS severity7.5
High
EPSS probability0.81%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource exhaustion in Ovarro TBox firmware 1.45 and earlier allows remote attackers to crash the RTU via malformed Modbus frames. The main RTU program assumes every received Modbus frame is valid and processes a crafted invalid packet without validation. Unauthenticated network access to the Modbus service is sufficient, and exploitation interrupts the controller's monitoring and control functions.

The record

CVE
CVE-2021-22642
Published
Jul 28, 2022
Updated
Apr 17, 2025
Vendor
Ovarro
Product
TBox
Classifications
CWE-400, T0814
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 28, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 17, 2025Record 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=LT2
  2. Affected versionversion=MS-CPU32
  3. Affected versionversion=MS-CPU32-S2
  4. Affected versionversion=RM2
  5. Affected versionversion=TG2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Ovarro · TBoxversion=LT2; version=MS-CPU32; version=MS-CPU32-S2; version=RM2; version=TG2

Published CVSS scores

7.5ICS-CERTCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
T0814Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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