Use of insufficiently random values in Siemens products - CVE-2021-37186
Published: September 16, 2021
Vulnerability identifier: #VU56654
CSH Severity: Low
CVSS v4: 5.3 [CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2021-37186
CWE-ID: CWE-330
Exploitation vector: Adjecent network
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to compromise the target system.
The vulnerability exists due to the underlying TCP/IP stack does not properly calculate the random numbers used as ISN (Initial Sequence Numbers). A remote attacker on the local network can spoof the connection and gain access to sensitive information.
Affected software
SIMATIC RTU 3000
LOGO! CMR2020
LOGO! CMR2040
LOGO! CMR2020
LOGO! CMR2040
How to mitigate CVE-2021-37186
Install updates from vendor's website.
LOGO! CMR2020 - update to 2.2
LOGO! CMR2040 - update to 2.2
LOGO! CMR2040 - update to 2.2