CVE-2020-27632
First published: Wed Mar 10 2021(Updated: )
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.
Credit: cve@mitre.org
| Affected Software | Affected Version | How to fix |
|---|---|---|
| open-iscsi | ||
| CycloneTCP | ||
| Multiple NDKTCPIP, Version 2.25 and prior | ||
| butok FNET | ||
| Contiki OS | ||
| uC/TCP-IP | ||
| Contiki-NG | ||
| uIP (EOL) | ||
| altran picoTCP-NG | ||
| picoTCP | ||
| MPLAB Net | ||
| Multiple Nucleus NET | ||
| Multiple Nucleus ReadyStart for ARM, MIPS, and PPC | ||
| Siemens Simatic MV420 | <7.0.6 | |
| Siemens Simatic MV420 Firmware | ||
| Siemens Simatic MV440 | <7.0.6 | |
| Siemens SIMATIC MV440 HR |
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Reference Links
Frequently Asked Questions
What is CVE-2020-27632?
CVE-2020-27632 is a vulnerability in SIMATIC MV400 family versions prior to v7.0.6 where the ISN generator is initialized with a constant value and has constant increments, allowing an attacker to predict and hijack TCP sessions.
Which software versions are affected by CVE-2020-27632?
SIMATIC MV400 family versions prior to v7.0.6 are affected by CVE-2020-27632.
How severe is CVE-2020-27632?
CVE-2020-27632 has a severity rating of 7.5 (high).
How can I fix CVE-2020-27632?
To fix CVE-2020-27632, it is recommended to update the affected SIMATIC MV400 family device to version v7.0.6 or later.
Where can I find more information about CVE-2020-27632?
You can find more information about CVE-2020-27632 at the following references: [Siemens CERT Portal](https://cert-portal.siemens.com/productcert/pdf/ssa-599268.pdf), [CISA ICS Advisories](https://www.cisa.gov/news-events/ics-advisories/icsa-21-042-01), [Forescout - Numberjack Weak ISN Generation in Embedded TCP/IP Stacks](https://www.forescout.com/resources/numberjack-weak-isn-generation-in-embedded-tcpip-stacks/).
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- agent/severity
- agent/weakness
- agent/references
- agent/description
- collector/mitre-cve
- source/MITRE
- agent/last-modified-date
- agent/event
- agent/first-publish-date
- agent/trending
- agent/source
- collector/ics-cert-advisory
- source/ICS
- agent/software-canonical-lookup
- agent/software-canonical-lookup-request
- agent/author
- agent/softwarecombine
- agent/tags
- collector/nvd-index
- collector/nvd-api
- vendor/multiple
- canonical/open-iscsi
- canonical/cyclonetcp
- canonical/multiple ndktcpip, version 2.25 and prior
- canonical/butok fnet
- canonical/contiki os
- canonical/uc/tcp-ip
- canonical/contiki-ng
- canonical/uip (eol)
- canonical/altran picotcp-ng
- canonical/picotcp
- canonical/mplab net
- canonical/multiple nucleus net
- canonical/multiple nucleus readystart for arm, mips, and ppc
- vendor/siemens
- canonical/siemens simatic mv420
- canonical/siemens simatic mv420 firmware
- canonical/siemens simatic mv440
- canonical/siemens simatic mv440 hr