Siemens SIMATIC Devices Integer Overflow or Wraparound (CVE-2020-12762)

high Tenable OT Security Plugin ID 503850

Synopsis

The remote OT asset is affected by a vulnerability.

Description

json-c through 0.14 has an integer overflow and out-of-bounds write via a large JSON file, as demonstrated by printbuf_memappend.

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.

See Also

https://cert-portal.siemens.com/productcert/pdf/ssa-637483.pdf

https://cert-portal.siemens.com/productcert/html/ssa-398330.html

https://support.industry.siemens.com/cs/ww/en/view/109478459/

https://cert-portal.siemens.com/productcert/pdf/ssa-794697.pdf

https://support.industry.siemens.com/cs/ww/en/view/109827684/

https://support.industry.siemens.com/cs/ww/en/view/109812610/

Plugin Details

Severity: High

ID: 503850

Version: 1.1

Type: remote

Family: Tenable.ot

Published: 10/29/2025

Updated: 10/29/2025

Supported Sensors: Tenable OT Security

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 7

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

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

Vulnerability Information

CPE: cpe:/o:siemens:simatic_s7-1500_tm_mfp_firmware, cpe:/o:siemens:simatic_s7-1500_cpu_firmware:3.1.5, cpe:/o:siemens:siplus_s7-1500_cpu_firmware:3.1.5

Required KB Items: Tenable.ot/Siemens

Exploit Ease: No known exploits are available

Patch Publication Date: 9/13/2022

Vulnerability Publication Date: 9/13/2022

Reference Information

CVE: CVE-2020-12762

CWE: 190