CVE-2020-35685
Critical
Description
An issue was discovered in HCC Nichestack 3.0. The code that generates Initial Sequence Numbers (ISNs) for TCP connections derives the ISN from an insufficiently random source. As a result, an attacker may be able to determine the ISN of current and future TCP connections and either hijack existing ones or spoof future ones. (Proper ISN generation should aim to follow at least the specifications outlined in RFC 6528.)
SeverityCritical
CVSS9.1
Exploit probability—
ProductHcc-embedded Nichestack
PublishedAug 19, 2021
First seenAug 19, 2021
How to fix
Update
- siemens sentron_3wa_com190_firmware2.0.0 or later
- siemens sentron_3wl_com35_firmware1.2.0 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| hcc-embedded nichestack | 3.0 | — |
| siemens sentron_3wa_com190_firmware | v < 2.0.0 | 2.0.0 |
| siemens sentron_3wl_com35_firmware | v < 1.2.0 | 1.2.0 |
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