Cyber Resilience

CVE-2021-4465

HighPublic PoCDDoS

Published: 14 November 2025

Published
14 November 2025
Modified
15 April 2026
KEV Added
Patch
CVSS Score v4 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0047 64.9th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-4465 is a high-severity Uncontrolled Resource Consumption (CWE-400) vulnerability. Its CVSS base score is 8.7 (High).

Operationally, ranked in the top 35.1% 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

ReQuest Serious Play F3 Media Server versions 7.0.3.4968 (Pro), 7.0.2.4954, 6.5.2.4954, 6.4.2.4681, 6.3.2.4203, and 2.0.1.823 contain a remote denial-of-service vulnerability. The device can be shut down or rebooted by an unauthenticated attacker through a single crafted HTTP GET request, allowing…

more

remote interruption of service availability.

CWE(s)

Related Threats

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

Affected Assets

Play F3 Media Server
inferred from references and description; NVD did not file a CPE for this CVE

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