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CVE-2017-7901

A Predictable Value Range from Previous Values issue was discovered in Rockwell Automation Allen-Bradley MicroLogix 1100…

High8.6EPSS 9.0%
Published
Updated
Reserved
Assigned by
icscert

Description

A Predictable Value Range from Previous Values issue was discovered in Rockwell Automation Allen-Bradley MicroLogix 1100 programmable-logic controllers 1763-L16AWA, Series A and B, Version 16.00 and prior versions; 1763-L16BBB, Series A and B, Version 16.00 and prior versions; 1763-L16BWA, Series A and B, Version 16.00 and prior versions; and 1763-L16DWD, Series A and B, Version 16.00 and prior versions and Allen-Bradley MicroLogix 1400 programmable logic controllers 1766-L32AWA, Series A and B, Version 16.00 and prior versions; 1766-L32BWA, Series A and B, Version 16.00 and prior versions; 1766-L32BWAA, Series A and B, Version 16.00 and prior versions; 1766-L32BXB, Series A and B, Version 16.00 and prior versions; 1766-L32BXBA, Series A and B, Version 16.00 and prior versions; and 1766-L32AWAA, Series A and B, Version 16.00 and prior versions. Insufficiently random TCP initial sequence numbers are generated, which may allow an attacker to predict the numbers from previous values. This may allow an attacker to spoof or disrupt TCP connections, resulting in a denial of service for the target device.

Scores

CVSS scores of CVE-2017-7901, by who scored it
Scored byCVSSScoreVector
NVDNVD · Modified3.0High8.6CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H
EPSS (exploitation in 30 days)
9.0% · top 4.7% of all CVEs (2 Nov 2026)

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The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.6.

Weakness

Affected products

  • Rockwell Automation Allen-Bradley MicroLogix 1100 and 1400

    • affected Rockwell Automation Allen-Bradley MicroLogix 1100 and 1400

References (2)

Sources

The same CVE in the primary databases and aggregators, to check against.

Record last updated .