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How CVE-2025-20085 Works:
The vulnerability exists in the Modbus RTU over TCP functionality of Socomec DIRIS Digiware M-70 firmware version 1.6.9.
Modbus RTU over TCP encapsulates serial Modbus frames within TCP packets for network communication.
A specially crafted network packet sent to the Modbus TCP port (typically 502) triggers the flaw.
The packet contains malformed or unexpected data in the Modbus RTU over TCP header or payload.
This malformed data causes insufficient input validation during packet parsing by the device.
The parsing routine experiences memory corruption, such as a buffer overflow or logic error.
This corruption leads to a denial of service condition, crashing the Modbus service or device.
Simultaneously, the attack interferes with the device’s credential storage mechanism.
The vulnerability weakens stored credentials, forcing a revert to default documented credentials.
Default usernames and passwords become active, compromising device security.
An attacker can send this crafted packet without authentication, enabling remote exploitation.
The attack is network-based, requiring only access to the Modbus TCP port.
Exploitation results in device unavailability due to DoS and subsequent credential exposure.
The flaw stems from improper error handling and lack of bounds checking in firmware.
Affected systems include industrial energy meters using this specific firmware version.
Patches must address packet validation and credential management routines.
Mitigation involves filtering Modbus traffic and applying updates when released.
This vulnerability highlights risks in industrial protocol implementations.
Remote attackers can disrupt operations and gain unauthorized access easily.
Platform: Socomec DIRIS Digiware
Version: 1.6.9
Vulnerability: DoS Credential Weakening
Severity: Critical
date: 12/01/2025
Prediction: Patch expected 01/2026
What Undercode Say:
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Bash commands:
`nc -zv target 502`
`python3 exploit_cve.py`
`tcpdump port 502`
Codes:
import socket def send_packet(target_ip): packet = b'\x00\x01\x00\x00\x00\x06\x01\x03\x00\x00\x00\x01' s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) s.connect((target_ip, 502)) s.send(packet) s.close()
How Exploit:
Craft malicious Modbus packet.
Send to port 502.
Trigger DoS reset.
Use default credentials.
Protection from this CVE
Apply firmware patches.
Segment network traffic.
Disable unused ports.
Impact:
Service disruption.
Credential compromise.
Unauthorized access.
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Sources:
Reported By: nvd.nist.gov
Extra Source Hub:
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