#VU53228 Incorrect calculation in SCALANCE XM-400 and SCALANCE XR-500 - CVE-2020-28393

Vulnerability identifier: #VU53228

Vulnerability risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2020-28393

CWE-ID: CWE-682

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
SCALANCE XM-400
Hardware solutions / Routers & switches, VoIP, GSM, etc
SCALANCE XR-500
Hardware solutions / Routers & switches, VoIP, GSM, etc

Vendor: Siemens

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to incorrect calculation issue. A remote attacker can send a specially crafted OSPF packet and cause a denial of service condition.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

SCALANCE XM-400: before 6.4

SCALANCE XR-500: before 6.4

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External links
https://cert-portal.siemens.com/productcert/pdf/ssa-116379.pdf
https://us-cert.cisa.gov/ics/advisories/icsa-21-131-10

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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.