CVE-2021-33820 json
An issue was discovered in UniFi Protect G3 FLEX Camera Version UVC.v4.30.0.67.Attacker could send a huge amount of TCP SYN packet to make…
published 2021-06-18 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-20495
- cvss
- 7.5
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.9%
- EPSS 1.9% chance of exploitation in 30 days, percentile 80%
- public exploits
- 0
- none known
Summary
An issue was discovered in UniFi Protect G3 FLEX Camera Version UVC.v4.30.0.67.Attacker could send a huge amount of TCP SYN packet to make web service's resource exhausted. Then the web server is denial-of-service.
Exploit prediction
1.93% chance of exploitation in the next 30 days, higher than 80% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- github.com https://github.com/Jian-Xian/CVE-POC/blob/master/CVE-2021-33820.md referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| NVD | 2.0 | 5.0 | AV:N/AC:L/Au:N/C:N/I:N/A:P |
References
-
github.com
/Jian-Xian/CVE-POC/blob/master/CVE-2021-33820.md
exploit, third-party-advisory
-
store.ui.com
/collections/unifi-protect-cameras/products/unifi-video-g3-flex-camera
product, vendor-advisory
-
linuxhint.com
/hping3/
third-party-advisory
Sources
- CVE List CVE-2021-33820
- NVD CVE-2021-33820
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.