EG4 Electronics EG4 Inverters (Update A)
1. EXECUTIVE SUMMARY
- CVSS v4 9.2
- ATTENTION: Exploitable remotely/low attack complexity
- Vendor: EG4 Electronics
- Equipment: EG4 Inverters
- Vulnerabilities: Cleartext Transmission of Sensitive Information, Download of Code Without Integrity Check, Observable Discrepancy, Improper Restriction of Excessive Authentication Attempts
2. RISK EVALUATION
Successful exploitation of these vulnerabilities could allow an attacker to intercept and manipulate critical data, install malicious firmware, hijack device access, and gain unauthorized control over the system.
3. TECHNICAL DETAILS
3.1 AFFECTED PRODUCTS
The following EG4 Electronics inverters are affected:
- EG4 12kPV: All versions
- EG4 18kPV: All versions
- EG4 Flex 21: All versions
- EG4 Flex 18: All versions
- EG4 6000XP: All versions
- EG4 12000XP: All versions
- EG4 GridBoss: All versions
3.2 VULNERABILITY OVERVIEW
3.2.1 CLEARTEXT TRANSMISSION OF SENSITIVE INFORMATION CWE-319
The MOD3 command traffic between the monitoring application and the inverter is transmitted in plaintext without encryption or obfuscation. This vulnerability may allow an attacker with access to a local network to intercept, manipulate, replay, or forge critical data, including read/write operations for voltage, current, and power configuration, operational status, alarms, telemetry, system reset, or inverter control commands, potentially disrupting power generation or reconfiguring inverter settings.
CVE-2025-52586 has been assigned to this vulnerability. A CVSS v3.1 base score of 6.9 has been calculated; the CVSS vector string is (AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L).
A CVSS v4 score has also been calculated for CVE-2025-52586. A base score of 7.5 has been calculated; the CVSS vector string is (AV:L/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N).
3.2.2 DOWNLOAD OF CODE WITHOUT INTEGRITY CHECK CWE-494
The affected product allows firmware updates to be downloaded from EG4's website, transferred via USB dongles, or installed through EG4's Monitoring Center (remote, cloud-connected interface) or via a serial connection, and can install these files without integrity checks. The TTComp archive format used for the firmware is unencrypted and can be unpacked and altered without detection.
CVE-2025-53520 has been assigned to this vulnerability. A CVSS v3.1 base score of 8.8 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H).
A CVSS v4 score has also been calculated for CVE-2025-53520. A base score of 8.6 has been calculated; the CVSS vector string is (AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N).
3.2.3 OBSERVABLE DISCREPANCY CWE-203
The public-facing product registration endpoint server responds differently depending on whether the S/N is valid and unregistered, valid but already registered, or does not exist in the database. Combined with the fact that serial numbers are sequentially assigned, this allows an attacker to gain information on the product registration status of different S/Ns.
CVE-2025-47872 has been assigned to this vulnerability. A CVSS v3.1 base score of 5.8 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N).
A CVSS v4 score has also been calculated for CVE-2025-47872. A base score of 6.9 has been calculated; the CVSS vector string is (AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N).
3.2.4 IMPROPER RESTRICTION OF EXCESSIVE AUTHENTICATION ATTEMPTS CWE-307
The affected product does not limit the number of attempts for inputting the correct PIN for a registered product, which may allow an attacker to gain unauthorized access using brute-force methods if they possess a valid device serial number. The API provides clear feedback when the correct PIN is entered. This vulnerability was patched in a server-side update on April 6, 2025.
CVE-2025-46414 has been assigned to this vulnerability. A CVSS v3.1 base score of 8.1 has been calculated; the CVSS vector string is (AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H).
A CVSS v4 score has also been calculated for CVE-2025-46414. A base score of 9.2 has been calculated; the CVSS vector string is (AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N).
3.3 BACKGROUND
- CRITICAL INFRASTRUCTURE SECTORS: Energy
- COUNTRIES/AREAS DEPLOYED: Worldwide
- COMPANY HEADQUARTERS LOCATION: United States
3.4 RESEARCHER
Jacob Krasnov and Anthony Rose of BC Security and Peter Kariuki of Ovanova reported these vulnerabilities to CISA.
4. MITIGATIONS
EG4 has acknowledged the vulnerabilities and is actively working on a fix, including new hardware expected to release by October 15, 2025. Until then, EG4 will actively monitor all installed systems and work with affected users on a case-by-case basis if anomalies are observed.
CVE-2025-47872: EG4 standardized the endpoint responses to eliminate the risk of enumerating sensitive data. This was deployed on August 14, 2025. No action is required from users.
CVE-2025-46414: EG4 deployed a fix on April 6, 2025. No action is required from users.
For more information, contact EG4.
CISA recommends users take defensive measures to minimize the risk of exploitation of these vulnerabilities, such as:
- Minimize network exposure for all control system devices and/or systems, ensuring they are not accessible from the Internet.
- Locate control system networks and remote devices behind firewalls and isolating them from business networks.
- When remote access is required, use more secure methods, such as Virtual Private Networks (VPNs), recognizing VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize VPN is only as secure as the connected devices.
CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.
CISA also provides a section for control systems security recommended practices on the ICS webpage on cisa.gov/ics. Several CISA products detailing cyber defense best practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.
CISA encourages organizations to implement recommended cybersecurity strategies for proactive defense of ICS assets.
Additional mitigation guidance and recommended practices are publicly available on the ICS webpage at cisa.gov/ics in the technical information paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies.
Organizations observing suspected malicious activity should follow established internal procedures and report findings to CISA for tracking and correlation against other incidents.
CISA also recommends users take the following measures to protect themselves from social engineering attacks:
- Do not click web links or open attachments in unsolicited email messages.
- Refer to Recognizing and Avoiding Email Scams for more information on avoiding email scams.
- Refer to Avoiding Social Engineering and Phishing Attacks for more information on social engineering attacks.
No known public exploitation specifically targeting these vulnerabilities has been reported to CISA at this time.
5. UPDATE HISTORY
- August 7, 2025: Initial Publication
- August 19, 2025: Update A - Updated mitigation details for CVE-2025-47872. Added two additional researchers.
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