What is the CVSS score of CVE-2021-33721?

CVE-2021-33721 has a CVSS 3.1 base score of 7.2 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 2.7%.

Is there a patch available for CVE-2021-33721?

Yes, a patch is available for CVE-2021-33721. Update the affected software to the latest version immediately.

Sinec Network Management System CVE-2021-33721

HIGH

OS Command Injection (CWE-78)

2021-08-10 productcert@siemens.com

RCE Command Injection Siemens Sinec Network Management System

7.2

CVSS 3.1 · NVD

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Vulnerability Assessment

Weakness	CWE CWE-78 OWASP Top 10:2025 A05:2025 - Injection ASVS 5.0 V1 - Encoding and Sanitization OS command sanitization, avoid shell exec MITRE ATT&CK 2 techniques across 1 tactic: Execution 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 7.2 (HIGH). Attack characteristics: network attack vector, low complexity, high privileges required, no user interaction not required.
Exploit ScenarioDerived	A remote attacker could execute arbitrary operating system commands on the host by sending crafted requests to the affected application.

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

Patch available 2.7% exploitation probability (EPSS)

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AnalysisAI

A vulnerability has been identified in SINEC NMS (All versions < V1.0 SP2). Rated high severity (CVSS 7.2), this vulnerability is remotely exploitable, low attack complexity. This OS Command Injection vulnerability could allow attackers to execute arbitrary operating system commands on the host.

RemediationAI

A vendor patch is available. Apply the latest security update as soon as possible. Avoid passing user input to shell commands. Use language-specific APIs instead of shell execution. Apply strict input validation with allowlists.

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 OS Command Injection (CWE-78), which allows attackers to execute arbitrary operating system commands on the host. A vulnerability has been identified in SINEC NMS (All versions < V1.0 SP2). The affected application incorrectly neutralizes special elements when creating batch operations which could lead to command injection. An authenticated remote attacker with administrative privileges could exploit this vulnerability to execute arbitrary code on the system with system privileges. Affected products include: Siemens Sinec Network Management System.

Severity by source

NVD PRIMARY 7.2 HIGH

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

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector

Network

Attack Complexity

Low

Privileges Required

High

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

DescriptionNVD

A vulnerability has been identified in SINEC NMS (All versions < V1.0 SP2). The affected application incorrectly neutralizes special elements when creating batch operations which could lead to command injection. An authenticated remote attacker with administrative privileges could exploit this vulnerability to execute arbitrary code on the system with system privileges.

Threat Intelligence Overview

EPSS Score

2.7%

Top 16% 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 2.7%

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.