What is the CVSS score of CVE-2021-40142?

CVE-2021-40142 has a CVSS 3.1 base score of 7.5 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. EPSS exploitation probability: 2.6%.

Is there a patch available for CVE-2021-40142?

Yes, a patch is available for CVE-2021-40142. Update the affected software to the latest version immediately.

Telecontrol Server Basic CVE-2021-40142

HIGH

Buffer Overflow (CWE-119)

2021-08-27 cve@mitre.org

Buffer Overflow Denial Of Service Siemens Telecontrol Server Basic Simatic Wincc Simatic Wincc Runtime Simatic Net Pc Simatic Process Historian Opc Ua Server Firmware Local Discover Server Simatic Wincc Unified Scada Runtime Opcfoundation

7.5

CVSS 3.1 · NVD

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Vulnerability Assessment

Weakness	CWE CWE-119 ASVS 5.0 V15 - Secure Coding and Architecture Bounds checking, buffer size validation MITRE ATT&CK 2 techniques across 2 tactics: Execution, Privilege Escalation The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. Sign in to read
Impact	CVSS score of 7.5 (HIGH). Attack characteristics: network attack vector, low complexity, no privileges required, no user interaction not required.
Exploit ScenarioDerived	A remote attacker could corrupt memory to execute arbitrary code or crash the application by sending crafted requests to the affected application. No authentication is required to exploit this vulnerability.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).

Patch available 2.6% exploitation probability (EPSS)

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AnalysisAI

In OPC Foundation Local Discovery Server (LDS) before 1.04.402.463, remote attackers can cause a denial of service (DoS) by sending carefully crafted messages that lead to Access of a Memory Location. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This Buffer Overflow vulnerability could allow attackers to corrupt memory to execute arbitrary code or crash the application.

RemediationAI

A vendor patch is available. Apply the latest security update as soon as possible. Use memory-safe languages or bounds-checking. Enable ASLR, DEP/NX, stack canaries. Use safe string functions.

Affects your stack

Find out whether the stacks and servers you run are on an affected version.

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

This vulnerability is classified as Buffer Overflow (CWE-119), which allows attackers to corrupt memory to execute arbitrary code or crash the application. In OPC Foundation Local Discovery Server (LDS) before 1.04.402.463, remote attackers can cause a denial of service (DoS) by sending carefully crafted messages that lead to Access of a Memory Location After the End of a Buffer. Affected products include: Opcfoundation Local Discover Server, Siemens Simatic Process Historian Opc Ua Server Firmware, Siemens Simatic Net Pc, Siemens Simatic Wincc, Siemens Simatic Wincc Runtime. Version information: before 1.04.402.463.

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

NVD PRIMARY 7.5 HIGH

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

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

DescriptionNVD

Threat Intelligence Overview

EPSS Score

2.6%

Top 17% exploitable

Data Quality

2 sources

Confidence: Low

NVD

CVE.org

EPSS

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue

Severity HIGH

CISA KEV No

Public POC No

EPSS 2.6%

Patch available Yes

Active threat No

Deciding rule

HIGH severity (CVSS 7.0-8.9)

What every action level means

Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.

Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.

This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.

This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.

Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived

Scheduled

Exploitation· derived

None

System Exposure· derived

Open

Automatable· derived

Yes

Human Impact· derived

Medium

Priority Score

Low Medium High Critical

KEV: 0

EPSS: +3

CVSS: +38

PoC: 0

Weaponized: 0

Threat intel: 0

Gov advisory: 0

Attack Technique

Buffer Overflow HIGH

A buffer overflow occurs when a program writes more data to a memory buffer than it was allocated to hold, causing the excess data to spill into adjacent memory regions.

Denial of Service MEDIUM

Denial of Service attacks render applications or systems unavailable by overwhelming resources or triggering failure conditions.

Affected Products (CPE)NVD

cpe:2.3:a:opcfoundation:local_discover_server:*:*:*:*:*:*:*:*

cpe:2.3:o:siemens:simatic_process_historian_opc_ua_server_firmware:*:*:*:*:*:*:*:*

cpe:2.3:o:siemens:simatic_process_historian_opc_ua_server_firmware:2022:-:*:*:*:*:*:*

cpe:2.3:a:siemens:simatic_net_pc:14:-:*:*:*:*:*:*

cpe:2.3:a:siemens:simatic_net_pc:15:-:*:*:*:*:*:*

cpe:2.3:a:siemens:simatic_net_pc:16:-:*:*:*:*:*:*

cpe:2.3:a:siemens:simatic_net_pc:17:-:*:*:*:*:*:*

cpe:2.3:a:siemens:simatic_wincc:-:*:*:*:*:*:*:*

cpe:2.3:a:siemens:simatic_wincc_runtime:-:*:*:*:professional:*:*:*

cpe:2.3:a:siemens:simatic_wincc_unified_scada_runtime:-:*:*:*:*:*:*:*

cpe:2.3:a:siemens:telecontrol_server_basic:3.0:*:*:*:*:*:*:*

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