Schneider Electric Modicon Modbus Protocol Authentication Bypass by Capture-replay

Published 9 y ago 2017-06-30 · modified 4 mo ago 2026-06-17 · JSON

CVSS

9.8

v3.1 · CNA

CISA KEV

not known exploited

EPSS

5.6%

percentile 93%

Public exploits

none known

An authentication bypass by capture-replay issue was discovered in Schneider Electric Modicon Modbus Protocol. Sensitive information is transmitted in cleartext in the Modicon Modbus protocol, which may allow an attacker to replay the following commands: run, stop, upload, and download.

CISA SSVC assessment

Exploitation: none
Automatable: yes
Technical impact: total
Assessed: 5 mo ago 2026-05-28

Exploit prediction (EPSS)

5.60% probability of exploitation in the next 30 days, higher than 93% of all scored CVEs.

CVSS scores

Assigned by	Version	Score	Vector
CISA ADP	3.1	9.8	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`
CNA	3.1	9.8	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`
NVD	3.0	9.8	`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`
NVD	2.0	7.5	`AV:N/AC:L/Au:N/C:P/I:P/A:P`

Affected products

Schneider Electric Modicon Modbus Protocol

Classification

Weakness

CWE-294 Authentication Bypass by Capture-replay
CWE-287 Improper Authentication

References

ics-cert.us-cert.gov /advisories/ICSA-17-101-01 · x_refsource_MISC, x_transferred
securityfocus.com /bid/97562 · vdb-entry, x_refsource_BID, x_transferred
github.com /cisagov/CSAF/blob/develop/csaf_files/OT/white/2017/icsa-17-101-01.json
se.com /us/en/download/document/SEVD-2017-065-01/

Sources

CVE List: CVE-2017-6034
NVD: CVE-2017-6034

vulnwire keeps one entry per vulnerability: the CVE id wins, then GHSA; records that alias each other are merged. Machine-readable: JSON.

Summary