CVE-2021-21728

Name: CVE-2021-21728
Creator: NVD / NIST
Published: 2021-04-09T18:15:13.833+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.3/10EPSS 0.96%

Last modified Jun 17, 2026

CVE-2021-21728 is a medium-severity vulnerability rated 5.3/10 on the CVSS scale. A ZTE product has a configuration error vulnerability. Because a certain port is open by default, an attacker can consume system processing resources by flushing a large number of packets to the port, and successfully exploiting this vulnerability could reduce system processing capabilities. EPSS estimates a 0.96% chance of exploitation in the next 30 days.

Description

A ZTE product has a configuration error vulnerability. Because a certain port is open by default, an attacker can consume system processing resources by flushing a large number of packets to the port, and successfully exploiting this vulnerability could reduce system processing capabilities. This affects: ZXA10 C300M all versions up to V4.3P8.

Metrics

CVSS 3.1

5.3/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

EPSS Probability

0.96%

56.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-400

Affected Software

Vendor	Product	Versions
Zte	Zxa10 C300m Firmware	< 4.5

References

https://support.zte.com.cn/support/news/LoopholeInfoDetail.aspx?newsId=1014784Vendor Advisory
https://support.zte.com.cn/support/news/LoopholeInfoDetail.aspx?newsId=1014784Vendor Advisory

Timeline

Published: Apr 9, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-21728?

How severe is CVE-2021-21728?

CVE-2021-21728 has a CVSS score of 5.3/10 (MEDIUM severity). The EPSS model estimates a 0.96% probability of exploitation in the next 30 days.

How do I fix CVE-2021-21728?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-21728?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST