#VU60530 Operation on a Resource after Expiration or Release in Siemens products - CVE-2021-37185

Vulnerability identifier: #VU60530

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-2021-37185

CWE-ID: CWE-672

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
SIMATIC ET 200SP Open Controller CPU 1515SP PC2
Server applications / SCADA systems
SIMATIC S7-1500 Software Controller
Server applications / SCADA systems
SIMATIC S7-PLCSIM Advanced
Server applications / SCADA systems
SIMATIC S7-1200 CPU family
Hardware solutions / Firmware
SIMATIC S7-1500 CPU
Hardware solutions / Firmware
SIMATIC Drive Controller
Hardware solutions / Firmware
SIMATIC TIM 1531 IRC
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 operation on a resource after expiration or release in a PLC. A remote attacker can send a specially crafted packet and perform a denial of service (DoS) attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

SIMATIC ET 200SP Open Controller CPU 1515SP PC2: All versions

SIMATIC S7-1200 CPU family: 4.5 - 4.5.1

SIMATIC S7-1500 CPU: 2.9.2 - 2.9.3

SIMATIC S7-1500 Software Controller: All versions

SIMATIC S7-PLCSIM Advanced: All versions

SIMATIC Drive Controller: before 2.9.4

SIMATIC TIM 1531 IRC: before 2.2

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External links
https://cert-portal.siemens.com/productcert/pdf/ssa-838121.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.