CVE-2021-21727
A ZTE product has a DoS vulnerability. A remote attacker can amplify traffic by sending carefully...
A ZTE product has a DoS vulnerability. A remote attacker can amplify traffic by sending carefully constructed IPv6 packets to the affected devices, which eventually leads to device denial of service. This affects:<ZXHN F623><All versions up to V6.0.0P3T33>
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
A ZTE product has a DoS vulnerability. A remote attacker can amplify traffic by sending carefully constructed IPv6 packets to the affected devices, which eventually leads to device denial of service. This affects:<ZXHN F623><All versions up to V6.0.0P3T33>
- Record
CVE-2021-21727- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - CVSS 2.0
- 7.8 High
AV:N/AC:L/Au:N/C:N/I:N/A:C - Updated
- 2026-11-02
CVE List No score
A ZTE product has a DoS vulnerability. A remote attacker can amplify traffic by sending carefully constructed IPv6 packets to the affected devices, which eventually leads to device denial of service. This affects:<ZXHN F623><All versions up to V6.0.0P3T33>
- Record
CVE-2021-21727- Updated
- 2026-11-02
EUVDEUVD-2021-8899 No score
A ZTE product has a DoS vulnerability. A remote attacker can amplify traffic by sending carefully constructed IPv6 packets to the affected devices, which eventually leads to device denial of service. This affects:<ZXHN F623><All versions up to V6.0.0P3T33>
- Record
EUVD-2021-8899- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-8q85-4h38-w789 No score
A ZTE product has a DoS vulnerability. A remote attacker can amplify traffic by sending carefully...
A ZTE product has a DoS vulnerability. A remote attacker can amplify traffic by sending carefully constructed IPv6 packets to the affected devices, which eventually leads to device denial of service. This affects:<ZXHN F623><All versions up to V6.0.0P3T33>
- Record
GHSA-8q85-4h38-w789- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-21727 is a high vulnerability (CVSS 7.5) in Zte Zxhn F623 Firmware, published March 29, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.44%, the 73rd percentile. No source names a fixed version.