CVE-2025-2403VulnerabilityPublished 24 Jun 2025Updated 25 Jun 2025

CVE-2025-2403: Hitachi Energy Relion 670/650 and SAM600-IO · Unthrottled Resource Allocation

Affects Hitachi Energy Relion 670/650 and SAM600-IOSource CVE Database V5

Not known to be exploited · CVSS 7.5 High.

Data as of 26 Oct 2026, 06:26 UTC

CVSS 3.1 base score

7.5High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.3% chance of exploitation in 30 days – higher than 30% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 24 Jun 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
Hitachi Energy Relion 670/650 and SAM600-IO	Affected =2.2.6.0 =2.2.5.6 =2.2.4.4 =2.2.3.7 =2.2.2.6	Fixed in–

AI-suggested

1. Immediate network-level mitigation: Implement strict network segmentation and access control lists (ACLs) to restrict traffic to Relion 670/650 and SAM600-IO devices only from trusted management and operational networks. 2. Rate limiting and traffic prioritization: Deploy network devices capable of rate limiting and prioritizing legitimate protection traffic to prevent resource exhaustion attacks. 3. Monitoring and anomaly detection: Enhance monitoring of network traffic patterns to these devices to detect unusual spikes or malformed packets indicative of exploitation attempts. 4. Vendor coordination: Engage with Hitachi Energy to obtain patches or firmware updates addressing this vulnerability as soon as they become available. 5. Incident response readiness: Prepare operational procedures to quickly isolate affected devices and switch to backup protection schemes in case of suspected DoS attacks. 6. Firmware version auditing: Inventory and verify device firmware versions to identify and prioritize updates for vulnerable versions 2.2.2.6 through 2.2.6.0. 7. Harden device configurations: Disable unnecessary network services and interfaces on the devices to reduce attack surface. 8. Conduct penetration testing and red teaming exercises focused on these devices to validate defenses and detection capabilities.

Description

A denial-of-service vulnerability due to improper prioritization of network traffic over protection mechanism exists in Relion 670/650 and SAM600-IO series device that if exploited could potentially cause critical functions like LDCM (Line Distance Communication Module) to malfunction.

Impact

For European organizations, especially utilities and critical infrastructure operators, this vulnerability could have severe operational impacts. The Relion 670/650 and SAM600-IO devices are widely used in electrical substations for protection and automation. A successful DoS attack could disable or degrade protective relaying functions, leading to delayed fault detection and isolation, increasing the risk of cascading failures or prolonged outages. This could affect power distribution reliability, potentially causing blackouts or equipment damage. The impact is primarily on availability, with no direct confidentiality or integrity compromise, but the operational disruption could have significant downstream effects on service continuity and safety. Given the increasing digitization and interconnectivity of European power grids, such vulnerabilities could be leveraged in coordinated attacks targeting grid stability. The lack of required authentication and user interaction lowers the barrier for exploitation, increasing the threat level. Although no exploits are currently known, the critical nature of the devices and their deployment in essential services make this vulnerability a high priority for mitigation.

CWE-770Allocation of Resources Without Limits or Throttling (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #25
The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.
Requirements
Clearly specify the minimum and maximum expectations for capabilities, and dictate which behaviors are acceptable when resource allocation reaches limits.
Architecture and Design
Limit the amount of resources that are accessible to unprivileged users. Set per-user limits for resources. Allow the system administrator to define these limits. Be careful to avoid CWE-410.
Architecture and Design
Design throttling mechanisms into the system architecture. The best protection is to limit the amount of resources that an unauthorized user can cause to be expended.
OWASP Cheat Sheets
Abuse Case (opens in a new tab)
OWASP ASVS 4.0.3
V8.1.4 (opens in a new tab)
V13.4.1 (opens in a new tab)
V11.1.4 (opens in a new tab)
Attack patterns
XML Ping of the Death (opens in a new tab)
Exponential Data Expansion (opens in a new tab)
Serialized Data Parameter Blowup (opens in a new tab)
Serialized Data with Nested Payloads (opens in a new tab)
Oversized Serialized Data Payloads (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

publisher.hitachienergy.com/preview?DocumentID=8DBD000216&LanguageCode=en&DocumentPartId=&Action=Launch (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 24 Jun 2025, 12:09 UTC

WeaknessesCWE-770

Technical details

References

Community reviews

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