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Rtu520 Firmware CVE-2022-2081

HIGH
Out-of-bounds Write (CWE-787)
2024-01-04 cybersecurity@hitachienergy.com
7.5
CVSS 3.1 · NVD
View

Vulnerability Assessment

Weakness
CWE
OWASP Top 10:2025
A06:2021 - Vulnerable and Outdated Components
ASVS 5.0
V15 - Secure Coding and Architecture Bounds checking, write limits
MITRE ATT&CK

2 techniques across 2 tactics: Execution, Privilege Escalation

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

Impact

CVSS score of 7.5 (HIGH). Attack characteristics: network attack vector, low complexity, no privileges required, no user interaction not required. EPSS exploitation probability: 0.15%.

Exploit ScenarioDerived

A remote attacker could write data beyond allocated buffer boundaries leading to code execution or crashes by sending crafted requests to the affected application. No authentication is required to exploit this vulnerability.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).
No patch listed yet 0.2% exploitation probability (EPSS)

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AnalysisAIv1 – Mar 28, 2026

A vulnerability exists in the HCI Modbus TCP function included in the product versions listed above. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Earlier versions of this analysis (1)
v1 Mar 28, 2026 - 19:33 CVSS 7.5

Stack overflow in HCI Modbus TCP.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Validate write boundaries, use memory-safe languages, enable compiler protections (ASLR, stack canaries).

Affects your stack

Find out whether the stacks and servers you run are on an affected version.

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

This vulnerability is classified as Out-of-bounds Write (CWE-787), which allows attackers to write data beyond allocated buffer boundaries leading to code execution or crashes. A vulnerability exists in the HCI Modbus TCP function included in the product versions listed above. If the HCI Modbus TCP is enabled and configured, an attacker could exploit the vulnerability by sending a specially crafted message to the RTU500 in a high rate, causing the targeted RTU500 CMU to reboot. The vulnerability is caused by a lack of flood control which eventually if exploited causes an internal stack overflow in the HCI Modbus TCP function. Affected products include: Hitachienergy Rtu520 Firmware, Hitachienergy Rtu530 Firmware, Hitachienergy Rtu540 Firmware, Hitachienergy Rtu560 Firmware.

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  • Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

NVD PRIMARY 7.5 HIGH
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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
None
Integrity
None
Availability
High

DescriptionCVE.org

A vulnerability exists in the HCI Modbus TCP function included in the product versions listed above. If the HCI Modbus TCP is enabled and configured, an attacker could exploit the vulnerability by sending a specially crafted message to the RTU500 in a high rate, causing the targeted RTU500 CMU to reboot. The vulnerability is caused by a lack of flood control which eventually if exploited causes an internal stack overflow in the HCI Modbus TCP function.

Executive ViewAI

Why It Matters

Organizations using the HCI Modbus TCP function included in the product face notable risk from CVE-2022-2081, a out-of-bounds write vulnerability rated CVSS 7.5. Exploitation could allow attackers to corrupt memory, crash the application, or potentially execute arbitrary code. Organizations should apply vendor updates when available and consider compensating controls in the interim.

Business Impact: High
Compensating Controls

Apply vendor patch. If immediate patching is not feasible: (1) Enable ASLR and DEP where available; (2) Implement network segmentation; (3) Monitor for exploitation indicators.

Threat Intelligence Overview

EPSS Score
0.2%
Top 64% exploitable
Data Quality
3 sources
Confidence: Low

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 HIGH
CISA KEV No
Public POC No
EPSS 0.2%
Patch available No
Active threat No
Deciding rule
HIGH severity (CVSS 7.0-8.9)
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
High

Priority Score

38
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +38
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

A buffer overflow occurs when a program writes more data to a memory buffer than it was allocated to hold, causing the excess data to spill into adjacent memory regions.

Memory corruption occurs when a program writes data beyond the boundaries of allocated memory regions or accesses memory in unintended ways, violating the integrity of the process's address space.

Affected Products (CPE)CVE.org

cpe:2.3:o:hitachienergy:rtu520_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hitachienergy:rtu520_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hitachienergy:rtu520_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hitachienergy:rtu520_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hitachienergy:rtu520_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hitachienergy:rtu520_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hitachienergy:rtu520_firmware:13.3.1:*:*:*:*:*:*:*
cpe:2.3:o:hitachienergy:rtu530_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hitachienergy:rtu530_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hitachienergy:rtu530_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hitachienergy:rtu530_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hitachienergy:rtu530_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hitachienergy:rtu530_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hitachienergy:rtu530_firmware:13.3.1:*:*:*:*:*:*:*
cpe:2.3:o:hitachienergy:rtu540_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hitachienergy:rtu540_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hitachienergy:rtu540_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hitachienergy:rtu540_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hitachienergy:rtu540_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hitachienergy:rtu540_firmware:*:*:*:*:*:*:*:*
+ 8 more

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