CVE-2020-27632
In SIMATIC MV400 family versions prior to v7.0.6, the ISN generator is initialized with a...
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
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.
- Record
CVE-2020-27632- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N - CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:N/I:P/A:N - Updated
- 2026-11-02
CVE List No score
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.
- Record
CVE-2020-27632- Updated
- 2026-11-02
EUVDEUVD-2020-20139 No score
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.
- Record
EUVD-2020-20139- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-53pq-r3c7-x97x
In SIMATIC MV400 family versions prior to v7.0.6, the ISN generator is initialized with a...
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.
- Record
GHSA-53pq-r3c7-x97x- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N - Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2020-27632 is a high vulnerability (CVSS 7.5) in Siemens Simatic Mv420 Firmware, published March 10, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 2.14%, the 82nd percentile. No source names a fixed version.