CVE-2017-6030
The affected products generate insufficiently random TCP initial sequence numbers that may allow an attacker to predict the numbers from previous values.
Does this matter?
Lower severity and a low EPSS score (2.18%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.1
- 6.5 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L
- EPSS
- 2.18% probability · 82th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-343, CWE-331
- Affected
- schneider-electric/modicon m241 firmware · schneider-electric/modicon m251 firmware · schneider-electric/modicon m221 firmware
- Source
- ics-cert@hq.dhs.gov
EPSS 2.2% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- http://www.securityfocus.com/bid/97254Third Party Advisory, VDB Entry
- https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2017/icsa-17-089-02.json
- https://ics-cert.us-cert.gov/advisories/ICSA-17-089-02Third Party Advisory, US Government Resource
- http://www.securityfocus.com/bid/97254Third Party Advisory, VDB Entry
- https://ics-cert.us-cert.gov/advisories/ICSA-17-089-02Third Party Advisory, US Government Resource
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.