CVE-2026-1773
Denial of Service via Invalid U-Frame in IEC
Publication date: 2026-02-24
Last updated on: 2026-02-27
Assigner: Hitachi Energy
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| hitachienergy | rtu540_firmware | From 12.7.1 (inc) to 12.7.7 (inc) |
| hitachienergy | rtu540_firmware | From 13.5.1 (inc) to 13.5.4 (inc) |
| hitachienergy | rtu540_firmware | From 13.6.1 (inc) to 13.6.2 (inc) |
| hitachienergy | rtu540_firmware | 13.8.1 |
| hitachienergy | rtu540_firmware | From 13.7.1 (inc) to 13.7.8 (exc) |
| hitachienergy | rtu560_firmware | From 12.7.1 (inc) to 12.7.7 (inc) |
| hitachienergy | rtu560_firmware | From 13.5.1 (inc) to 13.5.4 (inc) |
| hitachienergy | rtu560_firmware | From 13.6.1 (inc) to 13.6.2 (inc) |
| hitachienergy | rtu560_firmware | 13.8.1 |
| hitachienergy | rtu560_firmware | From 13.7.1 (inc) to 13.7.8 (exc) |
| hitachienergy | rtu520_firmware | From 12.7.1 (inc) to 12.7.7 (inc) |
| hitachienergy | rtu520_firmware | From 13.5.1 (inc) to 13.5.4 (inc) |
| hitachienergy | rtu520_firmware | From 13.6.1 (inc) to 13.6.2 (inc) |
| hitachienergy | rtu520_firmware | 13.8.1 |
| hitachienergy | rtu520_firmware | From 13.7.1 (inc) to 13.7.8 (exc) |
| hitachienergy | rtu530_firmware | From 12.7.1 (inc) to 12.7.7 (inc) |
| hitachienergy | rtu530_firmware | From 13.5.1 (inc) to 13.5.4 (inc) |
| hitachienergy | rtu530_firmware | From 13.6.1 (inc) to 13.6.2 (inc) |
| hitachienergy | rtu530_firmware | 13.8.1 |
| hitachienergy | rtu530_firmware | From 13.7.1 (inc) to 13.7.8 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-184 | The product implements a protection mechanism that relies on a list of inputs (or properties of inputs) that are not allowed by policy or otherwise require other action to neutralize before additional processing takes place, but the list is incomplete. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability relates to the IEC 60870-5-104 protocol and involves a potential Denial of Service (DoS) impact caused by the reception of invalid U-format frames.
The product is only affected if the IEC 60870-5-104 bi-directional functionality is configured.
Even enabling secure communication according to IEC 62351-3 does not fix the vulnerability but can reduce the risk of it being exploited.
How can this vulnerability impact me? :
The vulnerability can lead to a Denial of Service condition, which means that the affected system could become unavailable or unresponsive when it receives invalid U-format frames.
This impact is significant as it can disrupt communication and operations relying on the IEC 60870-5-104 protocol, especially if bi-directional functionality is enabled.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
I don't know
How can this vulnerability be detected on my network or system? Can you suggest some commands?
I don't know
What immediate steps should I take to mitigate this vulnerability?
The vulnerability affects IEC 60870-5-104 when bi-directional functionality is configured. Enabling secure communication following IEC 62351-3 does not fully remediate the vulnerability but helps mitigate the risk of exploitation.