Siemens CP1604 and CP1616 Cleartext Transmission of Sensitive Information (CVE-2018-13808)

critical Tenable OT Security Plugin ID 502002


The remote OT asset is affected by a vulnerability.


A vulnerability has been identified in CP 1604 (All versions), CP 1616 (All versions). An attacker with network access to port 23/tcp could extract internal communication data or cause a Denial-of-Service condition. Successful exploitation requires network access to a vulnerable device. At the time of advisory publication no public exploitation of this vulnerability was known.

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The following text was originally created by the Cybersecurity and Infrastructure Security Agency (CISA). The original can be found at

Siemens recommends users update to version 2.8.

Siemens has identified the following specific workarounds and mitigations users can apply to reduce the risk:

- Disable the integrated web server. The web server is disabled in the default settings and its use is optional. Use in a productive environment is discouraged.
- Restrict access to the device to the internal or VPN network. Further restrict access to the web interface (80/TCP) and to the telnet port (23/TCP) to trusted IP addresses if possible.
- Do not click on links from unknown sources.

- Fixes for CVE-2018-13808 have also been released in versions v2.5.2.7, v2.6.2.2, and v2.7.2.1.

As a general security measure, Siemens strongly recommends protecting network access to devices with appropriate mechanisms. In order to operate the devices in a protected IT environment, Siemens recommends configuring the environment according to Siemens’ operational guidelines for industrial security (, and following the recommendations in the product manuals.

Additional information on industrial security by Siemens can be found at:

For more information on these vulnerabilities and associated software updates, please see Siemens security advisory SSA-559174 on their website:

See Also

Plugin Details

Severity: Critical

ID: 502002

Version: 1.3

Type: remote

Family: Tenable.ot

Published: 2/20/2024

Updated: 3/4/2024

Supported Sensors: Tenable OT Security

Risk Information


Risk Factor: Medium

Score: 5.2


Risk Factor: Medium

Base Score: 6.4

Temporal Score: 4.7

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:P

CVSS Score Source: CVE-2018-13808


Risk Factor: Critical

Base Score: 9.1

Temporal Score: 7.9

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:siemens:cp_1604_firmware, cpe:/o:siemens:cp_1616_firmware

Required KB Items: Tenable.ot/Siemens

Exploit Ease: No known exploits are available

Patch Publication Date: 4/17/2019

Vulnerability Publication Date: 4/17/2019

Reference Information

CVE: CVE-2018-13808

CWE: 200