CVE-2021-33818
An issue was discovered in UniFi Protect G3 FLEX Camera Version UVC.v4.30.0.67. Attackers can use...
An issue was discovered in UniFi Protect G3 FLEX Camera Version UVC.v4.30.0.67. Attackers can use slowhttptest tool to send incomplete HTTP request, which could make server keep waiting for the packet to finish the connection, until its resource exhausted. Then the web server is denial-of-service.
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
An issue was discovered in UniFi Protect G3 FLEX Camera Version UVC.v4.30.0.67. Attackers can use slowhttptest tool to send incomplete HTTP request, which could make server keep waiting for the packet to finish the connection, until its resource exhausted. Then the web server is denial-of-service.
- Record
CVE-2021-33818- 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
- 5.0 Medium
AV:N/AC:L/Au:N/C:N/I:N/A:P - Weakness
- CWE-400
- Updated
- 2026-11-02
CVE List No score
An issue was discovered in UniFi Protect G3 FLEX Camera Version UVC.v4.30.0.67. Attackers can use slowhttptest tool to send incomplete HTTP request, which could make server keep waiting for the packet to finish the connection, until its resource exhausted. Then the web server is denial-of-service.
- Record
CVE-2021-33818- Updated
- 2026-11-02
EUVDEUVD-2021-20493 No score
An issue was discovered in UniFi Protect G3 FLEX Camera Version UVC.v4.30.0.67. Attackers can use slowhttptest tool to send incomplete HTTP request, which could make server keep waiting for the packet to finish the connection, until its resource exhausted. Then the web server is denial-of-service.
- Record
EUVD-2021-20493- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-r7pq-69h8-pg3g No score
An issue was discovered in UniFi Protect G3 FLEX Camera Version UVC.v4.30.0.67. Attackers can use...
An issue was discovered in UniFi Protect G3 FLEX Camera Version UVC.v4.30.0.67. Attackers can use slowhttptest tool to send incomplete HTTP request, which could make server keep waiting for the packet to finish the connection, until its resource exhausted. Then the web server is denial-of-service.
- Record
GHSA-r7pq-69h8-pg3g- Weakness
- CWE-400
- 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-2021-33818 is a high vulnerability (CVSS 7.5) in Ui Camera G3 Flex Firmware, published June 18, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.93%, the 80th percentile. No source names a fixed version.