CVE-2021-47741

ZBL EPON ONU Broadband Router V100R001 Privilege Escalation via Configuration Endpoint

8.7 High

ZBL EPON ONU Broadband Router V100R001 contains a privilege escalation vulnerability that allows limited administrative users to elevate access by sending requests to configuration endpoints. Attackers can exploit the vulnerability by accessing the configuration backup or password page to disclose the super user password and gain additional privileged functionalities.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: Low
User interaction: None

What an attacker can affect

Confidentiality: High
Integrity: High
Availability: High

Exploit likelihood

0.29%Up 0.3 points since Jan 1, 2026

What each source reports

CVE List Score used 8.7

ZBL EPON ONU Broadband Router V100R001 Privilege Escalation via Configuration Endpoint

Record: CVE-2021-47741
CVSS 4.0: 8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Weakness: CWE-522
Updated: 2026-11-02

EUVDEUVD-2025-206085 8.7

Record: EUVD-2025-206085
CVSS 4.0: 8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Updated: 2026-11-02

GitHub AdvisoriesGHSA-chph-r4jm-2932 8.7

ZBL EPON ONU Broadband Router V100R001 contains a privilege escalation vulnerability that allows...

Record: GHSA-chph-r4jm-2932
CVSS 4.0: 8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Weakness: CWE-522
Updated: 2026-11-02

NVD 8.7

Record: CVE-2021-47741
CVSS 4.0: 8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Weakness: CWE-522
Updated: 2026-11-02

Affected products

zblchina zbl epon onu broadband router

History

History
Recorded	Changed	Sources
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, NVD

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2021-47741 is a high vulnerability (CVSS 8.7) in Zblchina Zbl Epon Onu Broadband Router, published December 31, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.29%, the 21st percentile. No source names a fixed version.