Incorrect permission assignment for critical resource in Siemens SIMATIC Software Products

1) Incorrect permission assignment for critical resource

EUVDB-ID: #VU54870

Risk: Low

CVSSv4.0: 4.4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-31894

CWE-ID: CWE-732 - Incorrect Permission Assignment for Critical Resource

Exploit availability: No

Description

The vulnerability allows a local user to compromise the target system.

The vulnerability exists due to incorrect permission assignment for critical resource. A local user can change the content of certain metafiles and subsequently manipulate parameters or the behavior of devices that would be later configured by the affected software.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

SIMATIC PCS 7: 8.2 - 9.0

SIMATIC PDM: All versions

SINAMICS STARTER: All versions

SIMATIC STEP 7: before 5.7

CPE2.3

• cpe:2.3:a:siemens:simatic_pcs_7:*:*:*:*:*:*:*:*
• cpe:2.3:a:siemens:simatic_pcs_7:8.2:*:*:*:*:*:*:*
• cpe:2.3:a:siemens:simatic_pcs_7:9.0:*:*:*:*:*:*:*
• cpe:2.3:a:siemens:simatic_pdm:*:*:*:*:*:*:*:*
• cpe:2.3:a:siemens:sinamics_starter:*:*:*:*:*:*:*:*
• cpe:2.3:a:siemens:simatic_step_7:*:*:*:*:*:*:*:*

External links

https://cert-portal.siemens.com/productcert/pdf/ssa-661034.pdf

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

The attacker would have to login to the system and perform certain actions in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.