CVE-2017-6030: schneider electric modicon m221

Vulnerability summary

CVE-2017-6030 is a medium (CVSS 6.5) vulnerability in schneider electric modicon m221. EPSS estimates a 2.14% chance of exploitation in the next 30 days, higher than 81.8% of scored vulnerabilities.

Timeline

1. 30-06-2017
   PublishedVulnerability first disclosed.
2. 04-06-2026
   Last modifiedVulnerability information updated.

Description

A predictable value range from previous values issue was discovered in Schneider Electric Modicon PLCs Modicon M221, firmware versions prior to Version 1.5.0.0, Modicon M241, firmware versions prior to Version 4.0.5.11, and Modicon M251, firmware versions prior to Version 4.0.5.11. The affected products generate insufficiently random TCP initial sequence numbers that may allow an attacker to predict the numbers from previous values. This may allow an attacker to spoof or disrupt TCP connections.

• CWE-343Predictable Value Range from Previous ValuesThe product's random number generator produces a series of values which, when observed, can be used to infer a relatively small range of possibilities for the next value that could be generated.
• CWE-331Insufficient EntropyThe product uses an algorithm or scheme that produces insufficient entropy, leaving patterns or clusters of values that are more likely to occur than others.