CVE-2021-33818
CVSS v3
7.5
HIGH
EPSS Score
1.9 %
exploit probability, as of 2026-09-25
CISA KEV
No
known exploited
Exploitation
—
SSVC status
Description
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.
Technical details
- Published
- 2021-06-18
Frequently asked questions
What is CVE-2021-33818?
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.
Is CVE-2021-33818 actively exploited?
Active exploitation of CVE-2021-33818 has not been confirmed. Its EPSS score was 1.9% on 2026-09-25, the estimated probability of exploitation in the next 30 days.
What is the CVSS score for CVE-2021-33818?
CVE-2021-33818 has a CVSS v3 base score of 7.5 (HIGH severity).
Is CVE-2021-33818 affecting your environment?
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