#VU56621 Buffer overflow in Siemens products - CVE-2021-33720

Vulnerability identifier: #VU56621

Vulnerability risk: Medium

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-33720

CWE-ID: CWE-119

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
SIPROTEC 5 relays with CPU variants CP150
Hardware solutions / Firmware
SIPROTEC 5 relays with CPU variants CP200
Hardware solutions / Firmware
SIPROTEC 5 relays with CPU variants CP050
Hardware solutions / Firmware
SIPROTEC 5 relays with CPU variants CP100
Hardware solutions / Firmware
SIPROTEC 5 relays with CPU variants CP300
Hardware solutions / Firmware

Vendor: Siemens

Description

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

The vulnerability exists due to a boundary error. A remote attacker can send a specially crafted packet, trigger memory corruption and cause a denial of service condition on the target system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

SIPROTEC 5 relays with CPU variants CP150: All versions

SIPROTEC 5 relays with CPU variants CP200: All versions

SIPROTEC 5 relays with CPU variants CP050: before 8.80

SIPROTEC 5 relays with CPU variants CP100: before 8.80

SIPROTEC 5 relays with CPU variants CP300: before 8.80

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External links
https://cert-portal.siemens.com/productcert/pdf/ssa-847986.pdf

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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.