What is CVE-2021-33721?

CVE-2021-33721 is a high-severity vulnerability in Siemens Sinec Network Management System, classified under OS Command Injection. CVSS score: 7.2/10. Published 2021-08-10.

How severe is CVE-2021-33721?

High severity. CVSS v3 base score is 7.2 out of 10.

RCE in Siemens Sinec Network Management System

CVE-2021-33721

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.

Vulnerability class: Command Injection (OS Command Injection)

Published 2021-08-10 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.027 (85.8th percentile), scored 2026-11-01.

Low probability of exploitation in the next 30 days, but still tracked. 86th percentile — 85.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.027 · newest: 0.027 · change: 0.000

Affected products

Siemens Sinec Network Management System — versions 1.0
Siemens Sinec Nms — versions All versions < V1.0 SP2

Weakness classification (CWE)

CWE-78 — OS Command Injection

References

cert-portal.siemens.com/productcert/pdf/ssa-756744.pdf (Patch, Vendor Advisory)

Frequently asked questions

What is CVE-2021-33721?: CVE-2021-33721 is a high-severity vulnerability in Siemens Sinec Network Management System, classified under OS Command Injection. CVSS score: 7.2/10. Published 2021-08-10.
How severe is CVE-2021-33721?: High severity. CVSS v3 base score is 7.2 out of 10.