An Improper Restriction of Excessive Authentication Attempts 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. There are no penalties for repeatedly entering incorrect passwords.

An Improper Restriction of Excessive Authentication Attempts 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. There are no penalties for repeatedly entering incorrect passwords.

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.CVE-2017-7901 has been assigned to this vulnerability. A CVSS v3 base score of 5.4 has been assigned; the CVSS vector string is (AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:L). The affected product reuses nonces, which may allow an attacker to capture and replay a valid request until the nonce is changed.CVE-2017-7902 has been assigned to this vulnerability. A CVSS v3 base score of 5.4 has been assigned; the CVSS vector string is (AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:L). User credentials are sent to the web server using the HTTP GET method, which may result in the credentials being logged. This could make user credentials available for unauthorized retrieval.CVE-2017-7899 has been assigned to this vulnerability. A CVSS v3 base score of 3.1 has been assigned; the CVSS vector string is (AV:L/AC:L/PR:H/UI:R/S:U/C:L/I:L/A:N). There are no penalties for repeatedly entering incorrect passwords.CVE-2017-7898 has been assigned to this vulnerability. A CVSS v3 base score of 9.8 has been assigned; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H). The affected products use a numeric password with a small maximum character size for the password.CVE-2017-7903 has been assigned to this vulnerability. A CVSS v3 base score of 9.8 has b…