What is CVE-2021-33728?

CVE-2021-33728 is a high-severity vulnerability in Siemens Sinec Nms, classified under Deserialization of Untrusted Data. CVSS score: 7.2/10. Published 2021-10-12.

How severe is CVE-2021-33728?

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

Deserialization in Siemens Sinec Nms

CVE-2021-33728

A vulnerability has been identified in SINEC NMS (All versions < V1.0 SP2 Update 1). The affected system allows to upload JSON objects that are deserialized to JAVA objects. Due to insecure deserialization of user-supplied content by the affected software, a privileged attacker could exploit this vulnerability by sending a crafted serialized Java object. An exploit could allow the attacker to execute arbitrary code on the device with root privileges.

Vulnerability class: Insecure Deserialization

Published 2021-10-12 · 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: 0.016 (74.3th percentile), scored 2026-10-08.

Low probability of exploitation in the next 30 days, but still tracked. 74th percentile — 74.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.016 · newest: 0.016 · change: 0.000

Affected products

Siemens Sinec Nms — versions All versions < V1.0 SP2 Update 1
Siemens Sinec Nms — versions 1.0

Weakness classification (CWE)

CWE-502 — Deserialization of Untrusted Data

References

cert-portal.siemens.com/productcert/pdf/ssa-163251.pdf (Patch, Vendor Advisory)

Frequently asked questions

What is CVE-2021-33728?: CVE-2021-33728 is a high-severity vulnerability in Siemens Sinec Nms, classified under Deserialization of Untrusted Data. CVSS score: 7.2/10. Published 2021-10-12.
How severe is CVE-2021-33728?: High severity. CVSS v3 base score is 7.2 out of 10.