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CVE-2017-6028: Schneider Electric Modicon M241 Firmware: Insufficiently Protected Credentials

CVE-2017-6028 is rated critical with a CVSS v3.1 base score of 9.8 and NVD lists 2 affected products, including Schneider Electric Modicon M241 Firmware. Per its scoring, it can be exploited over the network, without authentication, without any user interaction. The scored impact on confidentiality, integrity and availability is the highest available.

Vulnerability description

An Insufficiently Protected Credentials issue was discovered in Schneider Electric Modicon PLCs Modicon M241, all firmware versions, and Modicon M251, all firmware versions. Log-in credentials are sent over the network with Base64 encoding leaving them susceptible to sniffing. Sniffed credentials could then be used to log into the web application.

Severity breakdown

CVSS v3.1 9.8: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack vector: Network. Exploitable remotely over the network, with no need for local or physical access.
Attack complexity: Low. No special conditions; the attack can be repeated reliably.
Privileges required: None. No account or prior access is needed.
User interaction: None. No action from any user is needed.
Scope: Unchanged. Impact stays within the vulnerable component.
Confidentiality impact: High. Total loss of confidentiality; sensitive data can be fully disclosed.
Integrity impact: High. Total loss of integrity; data or system state can be fully modified.
Availability impact: High. Total loss of availability; the component can be shut down.

Underlying weakness

CWE-522: Insufficiently Protected Credentials

The product transmits or stores authentication credentials, but it uses an insecure method that is susceptible to unauthorized interception and/or retrieval.

Affected products

Schneider Electric Modicon M241 Firmware: up to and including 4.0.3.20
Schneider Electric Modicon M251 Firmware: up to and including 4.0.3.20