CVE-2017-6030

Schneider Electric Modicon PLCs Predictable Value Range from Previous Values

MEDIUM
6.5
CVSS Score
Published: June 30, 2017 at 02:35 AM UTC
Updated: June 17, 2026 at 01:21 AM UTC
6 products affected across 1 vendorModicon M221 FirmwareModicon M241 FirmwareModicon M251 Firmware

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Severity
MEDIUM6.5
Exploit prediction
EPSS 2%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v ≤ 1.1.1.5
schneider-electric-modicon-m221 (same device)
v ≤ 4.0.3.20
schneider-electric-modicon-m241 (same device)
v ≤ 4.0.3.20
schneider-electric-modicon-m251 (same device)
v < 1.5.0.0
Affected range stops below 1.5.0.0, so it looks safe — our inference, not a vendor statement
v < 4.0.5.11
Affected range stops below 4.0.5.11, so it looks safe — our inference, not a vendor statement
v < 4.0.5.11
Affected range stops below 4.0.5.11, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

References (3)

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

6.5MEDIUMCISA-ADP
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
LOW
Availability
LOW
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-343CWE-331

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