5.3

CVE-2021-27393: siemens nucleus_net Use of Insufficiently Random Values

CVSS: 5.3v3.1MediumModified
Published 22-04-2021Last modified 03-08-2024
Open JSON

Vulnerability summary

CVE-2021-27393 is a medium (CVSS 5.3) Use of Insufficiently Random Values vulnerability in siemens nucleus_net. EPSS estimates a 0.75% chance of exploitation in the next 30 days, higher than 54.1% of scored vulnerabilities.

Overall risk
21/100
0100
Low · default modelHow is this calculated?
CVSS score
5.3/10
010
Medium · v3.1 (NVD)
EPSS score
0.75%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 22-04-2021
    PublishedVulnerability first disclosed.
  2. 03-08-2024
    Last modifiedVulnerability information updated.

Description

A vulnerability has been identified in Nucleus NET (All versions), Nucleus ReadyStart V3 (All versions < V2013.08), Nucleus Source Code (Versions including affected DNS modules). The DNS client does not properly randomize UDP port numbers of DNS requests. That could allow an attacker to poison the DNS cache or spoof DNS resolving.

CVSS metrics

2 scores · 1 source · 2 versions

EPSS trend

Probability

0.75%

Chance of exploitation in the next 30 days

Percentile

54%

Versus all other CVEs

30-day change

0.00 pp

From 0.75% on 18-09-2026

18-09-202618-10-2026
EPSS score
0.75%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Siemens3 products

1 vendor · 3 products

References

1 links