CVE-2017-7901
A Predictable Value Range from Previous Values issue was discovered in Rockwell Automation Allen...
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.
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
- Low
- Integrity
- Low
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
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.
- Record
CVE-2017-7901- CVSS 3.0
- 8.6 High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H - CVSS 2.0
- 9.0 High
AV:N/AC:L/Au:N/C:P/I:P/A:C - Weakness
- CWE-343, CWE-330
- Updated
- 2026-11-02
CVE List No score
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.
- Record
CVE-2017-7901- Weakness
- CWE-343
- Updated
- 2026-11-02
EUVDEUVD-2017-16872 No score
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.
- Record
EUVD-2017-16872- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-9mhw-mx58-2jch
A Predictable Value Range from Previous Values issue was discovered in Rockwell Automation Allen...
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.
- Record
GHSA-9mhw-mx58-2jch- CVSS 3.0
- 8.6 High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H - Weakness
- CWE-330, CWE-343
- Updated
- 2026-11-02
Affected products
- rockwellautomation 1763-l16awa series a
- rockwellautomation 1763-l16awa series b
- rockwellautomation 1763-l16bbb series a
- rockwellautomation 1763-l16bbb series b
- rockwellautomation 1763-l16bwa series a
- rockwellautomation 1763-l16bwa series b
- rockwellautomation 1763-l16dwd series a
- rockwellautomation 1763-l16dwd series b
- rockwellautomation 1766-l32awa series a
- rockwellautomation 1766-l32awa series b
- rockwellautomation 1766-l32awaa series a
- rockwellautomation 1766-l32awaa series b
Show 8 moreShow less
- rockwellautomation 1766-l32bwa series a
- rockwellautomation 1766-l32bwa series b
- rockwellautomation 1766-l32bwaa series a
- rockwellautomation 1766-l32bwaa series b
- rockwellautomation 1766-l32bxb series a
- rockwellautomation 1766-l32bxb series b
- rockwellautomation 1766-l32bxba series a
- rockwellautomation 1766-l32bxba series b
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-2017-7901 is a high vulnerability (CVSS 8.6) in Rockwellautomation 1763-l16awa Series A, published June 30, 2017. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 9.05%, the 95th percentile. No source names a fixed version.