Siemens SIMATIC NET CP, SINEMA & SCALANCE Integer Overflow (CVE-2021-41991)

high Tenable OT Security Plugin ID 500650

Synopsis

The remote OT asset is affected by a vulnerability.

Description

The in-memory certificate cache in strongSwan before 5.9.4 has a remote integer overflow upon receiving many requests with different certificates to fill the cache and later trigger the replacement of cache entries. The code attempts to select a less-often-used cache entry by means of a random number generator, but this is not done correctly. Remote code execution might be a slight possibility.

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

Solution

Refer to the vendor advisory.

Plugin Details

Severity: High

ID: 500650

Version: 1.6

Type: remote

Family: Tenable.ot

Published: 4/28/2022

Updated: 3/10/2025

Supported Sensors: Tenable OT Security

Risk Information

VPR

Risk Factor: Low

Score: 3.6

CVSS v2

Risk Factor: Medium

Base Score: 5

Temporal Score: 3.9

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

CVSS Score Source: CVE-2021-41991

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.7

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:P/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:siemens:siplus_s7-1200_cp_1243-1_firmware:3.3.46, cpe:/o:siemens:simatic_cp_1542sp-1_firmware:2.2.28, cpe:/o:siemens:scalance_sc642-2c_firmware:2.3, cpe:/o:siemens:scalance_m876-4_%28eu%29_firmware:7.1, cpe:/o:siemens:scalance_m816-1_adsl-router_%28annex_a%29_firmware:7.1, cpe:/o:siemens:simatic_cp_1543-1_firmware:2.2.28, cpe:/o:siemens:scalance_m826-2_shdsl-router_firmware:7.1, cpe:/o:siemens:siplus_net_cp_1543-1_firmware:3.0.22, cpe:/o:siemens:siplus_et_200sp_cp_1543sp-1_isec_firmware:2.2.28, cpe:/o:siemens:scalance_m876-4_%28nam%29_firmware:7.1, cpe:/o:siemens:scalance_sc646-2c_firmware:2.3, cpe:/o:siemens:simatic_cp_1243-8_irc_firmware:3.3.46, cpe:/o:siemens:scalance_m874-3_firmware:7.1, cpe:/o:siemens:scalance_sc636-2c_firmware:2.3, cpe:/o:siemens:scalance_mum856-1_%28row%29_firmware:7.1, cpe:/o:siemens:scalance_mum853-1_%28eu%29_firmware:7.1, cpe:/o:siemens:scalance_mum856-1_%28eu%29_firmware:7.1, cpe:/o:siemens:scalance_m804pb_firmware:7.1, cpe:/o:siemens:scalance_m876-3_%28evdo%29_firmware:7.1, cpe:/o:siemens:scalance_sc632-2c_firmware:2.3, cpe:/o:siemens:simatic_cp_1545-1_firmware:1.1, cpe:/o:siemens:simatic_cp_1243-1_firmware:3.3.46, cpe:/o:siemens:simatic_cp_1243-7_lte_eu_firmware:3.3.46, cpe:/o:siemens:siplus_et_200sp_cp_1542sp-1_irc_tx_rail_firmware:2.2.28, cpe:/o:siemens:scalance_m816-1_adsl-router_%28annex_b%29_firmware:7.1, cpe:/o:siemens:simatic_cp_1242-7_v2_firmware:3.3.46, cpe:/o:siemens:scalance_m812-1_adsl-router_%28annex_a%29_firmware:7.1, cpe:/o:siemens:siplus_net_cp_1242-7_v2_firmware:3.3.46, cpe:/o:siemens:siplus_s7-1200_cp_1243-1_rail_firmware:3.3.46, cpe:/o:siemens:scalance_m876-3_%28rok%29_firmware:7.1, cpe:/o:siemens:ruggedcom_rm1224_lte%284g%29_eu_firmware:7.1, cpe:/o:siemens:siplus_et_200sp_cp_1543sp-1_isec_tx_rail_firmware:2.2.28, cpe:/o:siemens:scalance_m812-1_adsl-router_%28annex_b%29_firmware:7.1, cpe:/o:siemens:scalance_sc622-2c_firmware:2.3, cpe:/o:siemens:scalance_m874-2_firmware:7.1, cpe:/o:siemens:simatic_cp_1543sp-1_firmware:2.2.28, cpe:/o:siemens:simatic_cp_1542sp-1_irc_firmware:2.2.28, cpe:/o:siemens:scalance_s615_firmware:7.1, cpe:/o:siemens:ruggedcom_rm1224_lte%284g%29_nam_firmware:7.1, cpe:/o:siemens:simatic_cp_1243-7_lte_us_firmware:3.3.46

Required KB Items: Tenable.ot/Siemens

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 10/18/2021

Vulnerability Publication Date: 10/18/2021

Reference Information

CVE: CVE-2021-41991

CWE: 190

DSA: 4989

FEDORA: 2021-0b37146973, 2021-95fab6a482, 2021-b3df83339e

Detections

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