Siemens SIMATIC S7 Uncontrolled Resource Consumption (CVE-2019-13940)

high Tenable OT Security Plugin ID 500351

Synopsis

The remote OT asset is affected by a vulnerability.

Description

A vulnerability has been identified in SIMATIC ET 200pro IM154-8 PN/DP CPU (All versions < V3.X.17), SIMATIC ET 200pro IM154-8F PN/DP CPU (All versions < V3.X.17), SIMATIC ET 200pro IM154-8FX PN/DP CPU (All versions < V3.X.17), SIMATIC ET 200S IM151-8 PN/DP CPU (All versions < V3.X.17), SIMATIC ET 200S IM151-8F PN/DP CPU (All versions < V3.X.17), SIMATIC S7-1200 CPU family (incl. SIPLUS variants) (All versions < V4.1), SIMATIC S7-300 CPU 314C-2 PN/DP (All versions < V3.X.17), SIMATIC S7-300 CPU 315-2 PN/DP (All versions < V3.X.17), SIMATIC S7-300 CPU 315F-2 PN/DP (All versions < V3.X.17), SIMATIC S7-300 CPU 315T-3 PN/DP (All versions < V3.X.17), SIMATIC S7-300 CPU 317-2 PN/DP (All versions < V3.X.17), SIMATIC S7-300 CPU 317F-2 PN/DP (All versions < V3.X.17), SIMATIC S7-300 CPU 317T-3 PN/DP (All versions < V3.X.17), SIMATIC S7-300 CPU 317TF-3 PN/DP (All versions < V3.X.17), SIMATIC S7-300 CPU 319-3 PN/DP (All versions < V3.X.17), SIMATIC S7-300 CPU 319F-3 PN/DP (All versions < V3.X.17), SIMATIC S7-400 PN/DP V6 and below CPU family (incl. SIPLUS variants) (All versions), SIMATIC S7-400 PN/DP V7 CPU family (incl. SIPLUS variants) (All versions), SIMATIC WinAC RTX 2010 (All versions), SIMATIC WinAC RTX F 2010 (All versions), SIPLUS ET 200S IM151-8 PN/DP CPU (All versions < V3.X.17), SIPLUS ET 200S IM151-8F PN/DP CPU (All versions < V3.X.17), SIPLUS S7-300 CPU 314C-2 PN/DP (All versions < V3.X.17), SIPLUS S7-300 CPU 315-2 PN/DP (All versions < V3.X.17), SIPLUS S7-300 CPU 315F-2 PN/DP (All versions < V3.X.17), SIPLUS S7-300 CPU 317-2 PN/DP (All versions < V3.X.17), SIPLUS S7-300 CPU 317F-2 PN/DP (All versions < V3.X.17). Affected devices contain a vulnerability that could cause a denial of service condition of the web server by sending specially crafted HTTP requests to ports 80/tcp and 443/tcp. Beyond the web service, no other functions or interfaces are affected by the denial of service condition.

This plugin only works with Tenable.ot.
Please visit https://www.tenable.com/products/tenable-ot for more information.

Solution

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

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

- Restrict access to the device to the internal or VPN network. Further, if possible, restrict access to the web server (80/TCP, 443/TCP) to trusted IP addresses.
- If possible, disable the integrated web server. The web server is disabled in the default settings and its use is optional.
- For SIMATIC S7-1200 CPU family (including SIPLUS variants) Siemens recommends affected users update to v4.1 or any later version.
- For SIMATIC S7-300 PN/DP CPU family (including related ET200 CPUs and SIPLUS variants), Siemens recommends affected users update to v3.X.17 or later version.

For more information on this vulnerability and associated software updates, please see Siemens security advisory SSA-431678

Plugin Details

Severity: High

ID: 500351

Version: 1.7

Type: remote

Family: Tenable.ot

Published: 2/7/2022

Updated: 3/4/2024

Supported Sensors: Tenable OT Security

Risk Information

VPR

Risk Factor: Low

Score: 3.6

CVSS v2

Risk Factor: Medium

Base Score: 5

Temporal Score: 3.7

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

CVSS Score Source: CVE-2019-13940

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

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

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

Vulnerability Information

CPE: cpe:/o:siemens:simatic_s7-300_cpu_317-2_pn%2fdp_firmware, cpe:/o:siemens:simatic_s7-300_cpu_319-3_pn%2fdp_firmware, cpe:/o:siemens:simatic_s7-400_pn%2fdp_cpu_firmware, cpe:/o:siemens:siplus_cpu_1211c_firmware, cpe:/o:siemens:siplus_cpu_1212c_firmware, cpe:/o:siemens:siplus_cpu_1214c_firmware, cpe:/o:siemens:siplus_cpu_1215c_firmware, cpe:/o:siemens:siplus_s7-1200_firmware, cpe:/o:siemens:siplus_s7-300_cpu_314_firmware, cpe:/o:siemens:siplus_s7-300_cpu_315-2_dp_firmware, cpe:/o:siemens:siplus_s7-300_cpu_315-2_pn%2fdp_firmware, cpe:/o:siemens:siplus_s7-300_cpu_317-2_pn%2fdp_firmware, cpe:/o:siemens:s7-1200_cpu_1211c_firmware, cpe:/o:siemens:s7-1200_cpu_1212c_firmware, cpe:/o:siemens:s7-1200_cpu_1212fc_firmware, cpe:/o:siemens:s7-1200_cpu_1214c_firmware, cpe:/o:siemens:s7-1200_cpu_1214fc_firmware, cpe:/o:siemens:s7-1200_cpu_1215c_firmware, cpe:/o:siemens:s7-1200_cpu_1215fc_firmware, cpe:/o:siemens:s7-1200_cpu_1217c_firmware, cpe:/o:siemens:simatic_s7-300_cpu_315-2_pn%2fdp_firmware, cpe:/o:siemens:simatic_s7-300_cpu_315-2dp_firmware, cpe:/o:siemens:simatic_s7-300_cpu_317-2_dp_firmware

Required KB Items: Tenable.ot/Siemens

Exploit Ease: No known exploits are available

Patch Publication Date: 2/11/2020

Vulnerability Publication Date: 2/11/2020

Reference Information

CVE: CVE-2019-13940

CWE: 400

Detections

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