No exploitation reported

CVE-2021-21748

No exploitation reported by the sources we read.

Published2021-10-20
WeaknessCWE-787

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

ZTE MF971R product has two stack-based buffer overflow vulnerabilities. An attacker could exploit the vulnerabilities to execute arbitrary code.

Timeline

dates in UTC

2021-10-2016:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2021-21748?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-21748?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Zte mf971r firmwareversion to verify

Branch	Affected	Fixed in	Source
1.0	= v1.0.0b05	no fix published	NVD
1.x	= 1v1.0.0b06	no fix published	NVD
2.x	= 2v1.0.0b03	no fix published	NVD
—	= s2v1.0.0b03	no fix published	NVD
—	= sv1.0.0b05	no fix published	NVD

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Advisories and patches

support.zte.com.cnVendor Advisory

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

NVDCVSS 3.19.8read 2026-10-23
NVDCVSS 2.07.5read 2026-10-23
NVDweakness (CWE)CWE-787read 2026-10-23
FIRST EPSSEPSS score1.8 %2026-10-23

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published: 2021-10-20
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2021-21748?

ZTE MF971R product has two stack-based buffer overflow vulnerabilities. An attacker could exploit the vulnerabilities to execute arbitrary code.

Is CVE-2021-21748 actively exploited?

Active exploitation of CVE-2021-21748 has not been confirmed. Its EPSS score was 1.8% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-21748?

CVE-2021-21748 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

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