Cyber Resilience

CVE-2021-33818

HighPublic PoCDDoS

Published: 18 June 2021

Published
18 June 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0056 68.7th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-33818 is a high-severity Uncontrolled Resource Consumption (CWE-400) vulnerability in Ui Camera G3 Flex Firmware. Its CVSS base score is 7.5 (High).

Operationally, ranked in the top 31.3% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

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…

more

the web server is denial-of-service.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

ui
camera g3 flex firmware
uvc.v4.30.0.67

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-400

Limiting concurrent sessions directly prevents uncontrolled resource consumption by capping the number of active sessions per user or account.

addresses: CWE-400

Analysis identifies uncontrolled resource consumption indicative of denial-of-service or abuse attempts.

addresses: CWE-400

Contingency plan testing includes resource exhaustion scenarios to verify recovery, making it harder for attackers to sustain exploits that cause uncontrolled consumption.

addresses: CWE-400

Updated contingency plans include current procedures to detect, contain, and recover from resource exhaustion, limiting an attacker's ability to sustain impact from uncontrolled consumption.

addresses: CWE-400

Alternate site allows resumption of operations if resource exhaustion at the primary site is exploited to cause unavailability.

addresses: CWE-400

Alternate telecommunications services enable resumption of essential functions when primary services become unavailable due to uncontrolled resource consumption.

addresses: CWE-400

The team can analyze and respond to resource exhaustion incidents, reducing the impact of attacks that exploit uncontrolled consumption weaknesses.

addresses: CWE-400

Timely maintenance support and spare parts enable rapid recovery from failures induced by uncontrolled resource consumption, shortening the impact window of denial-of-service attacks.

References