Authentication bypass in Siemens Desigo PXC devices

1) Authentication bypass

EUVDB-ID: #VU10253

Risk: Low

CVSSv4.0: 8.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/U:Clear]

CVE-ID: CVE-2018-4834

CWE-ID: CWE-287 - Improper Authentication

Exploit availability: No

Description

The vulnerability allows a remote attacker to bypass authentication on the target system.

The weakness exists in Siemens Desigo PXC devices due to insufficient authentication checks. A remote attacker can bypass authentication and upload malicious firmware for further attacks.

Successful exploitation of the vulnerability may result in system compromise.

Mitigation

Update to version 6.00.204.

Vulnerable software versions

Desigo Operator Unit PXM20-E: 6.00

Desigo Automation Controllers for Integration PXC001-E.D: 6.00

Desigo Automation Controllers PXC00/64/128-U: 6.00

Desigo Automation Controllers Modular PXC00/50/100/200-E.D: 6.00

Desigo Automation Controllers Compact PXC12/22/36-E.D: 6.00

CPE2.3

• cpe:2.3:h:siemens:desigo_operator_unit_pxm20-e:6.00:*:*:*:*:*:*:*
• cpe:2.3:h:siemens:desigo_automation_controllers_for_integration_pxc001-ed:6.00:*:*:*:*:*:*:*
• cpe:2.3:h:siemens:desigo_automation_controllers_pxc00_64_128-u:6.00:*:*:*:*:*:*:*
• cpe:2.3:h:siemens:desigo_automation_controllers_modular_pxc00_50_100_200-ed:6.00:*:*:*:*:*:*:*
• cpe:2.3:h:siemens:desigo_automation_controllers_compact_pxc12_22_36-ed:6.00:*:*:*:*:*:*:*

External links

https://www.siemens.com/cert/pool/cert/siemens_security_advisory_ssa-824231.pdf

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.