Cyber Resilience

CVE-2021-35492

MediumPublic PoCDDoS

Published: 05 October 2021

Published
05 October 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.1298 94.2th percentile
Risk Priority 21 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-35492 is a medium-severity Allocation of Resources Without Limits or Throttling (CWE-770) vulnerability in Wowza Streaming Engine. Its CVSS base score is 6.5 (Medium).

Operationally, ranked in the top 5.8% 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

Wowza Streaming Engine through 4.8.11+5 could allow an authenticated, remote attacker to exhaust filesystem resources via the /enginemanager/server/vhost/historical.jsdata vhost parameter. This is due to the insufficient management of available filesystem resources. An attacker could exploit this vulnerability through the Virtual…

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Host Monitoring section by requesting random virtual-host historical data and exhausting available filesystem resources. A successful exploit could allow the attacker to cause database errors and cause the device to become unresponsive to web-based management. (Manual intervention is required to free filesystem resources and return the application to an operational state.)

CWE(s)

Related Threats

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

Affected Assets

wowza
streaming engine
≤ 4.8.11

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-770

This control implements explicit throttling on session allocation, addressing the weakness of allocating resources without limits.

addresses: CWE-770

Plan testing exercises resource allocation limits and throttling during simulated failures, directly addressing weaknesses that allow unbounded resource use.

addresses: CWE-770

Contingency plan updates ensure recovery strategies address unbounded resource allocation, making it harder for attackers to exploit lack of throttling to cause prolonged outages.

addresses: CWE-770

Provides continuity when unbounded resource allocation at the primary site leads to exhaustion and downtime.

addresses: CWE-770

Alternate services allow operations to continue when primary allocation of resources lacks limits or throttling.

addresses: CWE-770

Explicit planning of security-related actions requires defining limits, windows, and resource allocations, making allocation without throttling far less likely.

addresses: CWE-770

Measures of performance include tracking allocation behavior and throttling effectiveness, reducing the window for resource exhaustion attacks.

addresses: CWE-770

Imposes an inactivity-based limit on network resource allocation, throttling the number of concurrently held connections.

References