CVE-2020-27632

EUVD-2020-20139
In SIMATIC MV400 family versions prior to v7.0.6, the ISN generator is initialized with a constant value and has constant increments. An attacker could predict and hijack TCP sessions.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
7.5 HIGH
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: 58%
Affected Products (NVD)
VendorProductVersion
siemenssimatic_mv420_firmware
𝑥
< 7.0.6
siemenssimatic_mv440_firmware
𝑥
< 7.0.6
𝑥
= Vulnerable software versions
References
https://cert-portal.siemens.com/productcert/pdf/ssa-599268.pdf
https://www.cisa.gov/news-events/ics-advisories/icsa-21-042-01
https://www.forescout.com/resources/numberjack-weak-isn-generation-in-embedded-tcpip-stacks/
https://cert-portal.siemens.com/productcert/pdf/ssa-599268.pdf
https://www.cisa.gov/news-events/ics-advisories/icsa-21-042-01
https://www.forescout.com/resources/numberjack-weak-isn-generation-in-embedded-tcpip-stacks/