#VU25991 Use of Client-Side Authentication in Rockwell Automation products - CVE-2020-6988

Vulnerability identifier: #VU25991

Vulnerability risk: Medium

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

CVE-ID: CVE-2020-6988

CWE-ID: CWE-603

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
MicroLogix 1400 Controllers Series A
Client/Desktop applications / Software for system administration
MicroLogix 1400 Controllers Series B
Client/Desktop applications / Software for system administration
Allen-Bradley MicroLogix 1100
Hardware solutions / Office equipment, IP-phones, print servers
RSLogix 500 Software
Client/Desktop applications / Other client software

Vendor: Rockwell Automation

Description

The vulnerability allows a remote attacker to gain unauthorized access to sensitive information on the system.

The vulnerability exists due to a client/server product performs authentication within client code but not in server code. A remote attacker can send a specially crafted request from the RSLogix 500 software to the victim’s MicroLogix controller. The controller will then respond to the client with used password values to authenticate the user on the client-side.

This method of authentication may allow an attacker to bypass authentication altogether, disclose sensitive information, or leak credentials.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

MicroLogix 1400 Controllers Series A: All versions

MicroLogix 1400 Controllers Series B: 21.001

Allen-Bradley MicroLogix 1100: All versions

RSLogix 500 Software: before 11.00.00

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External links
https://ics-cert.us-cert.gov/advisories/icsa-20-070-06

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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.