CVE-2021-47741
ZBL EPON ONU Broadband Router V100R001 Privilege Escalation via Configuration Endpoint
- 8.7HighCVSS base score
- 0.29%Exploitation in 30 daysEPSS · top 79% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- YesPublic exploitsa reference or SSVC says so
Description
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.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. A reference of the record is tagged as an exploit. CISA's SSVC rates its exploitation: a proof of concept is public.
Show the exploits1
References tagged exploit1 reference
Timeline
ID reserved
By VulnCheck
- 8 days later
· 8 days later
Published
- 2 days later
· 2 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| VulnCheckCNA (assigner) | 4.0 | High8.7 | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N |
| VulnCheckCNA (assigner) | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N |
| NVDNVD · Deferred | 4.0 | High8.7 | CVSS: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 |
- EPSS (exploitation in 30 days)
- 0.29% · top 79% of all CVEs (11 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.7.
Affected products
Zblchina · ZBL EPON ONU Broadband Router
- affected 1.0
References
References5
- ExploitDB-49737 (opens in a new tab)exploit
- ZBL China Vendor Homepage (opens in a new tab)product
- Archived W&D Thailand Vendor Homepage (opens in a new tab)product
- Zero Science Lab Disclosure (ZSL-2021-5647) (opens in a new tab)third-party-advisory
- VulnCheck Advisory: ZBL EPON ONU Broadband Router V100R001 Privilege Escalation via Configuration Endpoint (opens in a new tab)third-party-advisory
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2025-206085 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2021-47741)Record last updated .