Vulnerability identifier: #VU21496

Vulnerability risk: Medium

CVSSv3.1: 6.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:C]

CVE-ID: CVE-2018-7843

CWE-ID: CWE-248

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Modicon Quantum
Hardware solutions / Firmware
Modicon Premium
Hardware solutions / Firmware
Modicon M340
Hardware solutions / Firmware
Modicon M580
Hardware solutions / Firmware

Vendor: Schneider Electric

Description
The vulnerability allows a remote attacker to cause a denial of service (DoS) condition on the target system.

The vulnerability exists due to uncaught exception vulnerability when reading memory blocks with an invalid data size or with an invalid data offset in the controller over Modbus. A remote attacker can cause a denial of service condition.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Modicon Quantum: All versions

Modicon Premium: All versions

Modicon M340: All versions

Modicon M580: 1.04 - 2.41

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External links
http://www.schneider-electric.com/en/download/document/SEVD-2019-134-11/
http://www.talosintelligence.com/vulnerability_reports/TALOS-2018-0738

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.