Cyber Resilience

CVE-2021-47368

HighDDoS

Published: 21 May 2024

Published
21 May 2024
Modified
02 April 2025
KEV Added
Patch
CVSS Score v3.1 8.1 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
EPSS Score 0.0005 15.3th percentile
Risk Priority 16 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-47368 is a high-severity Uncontrolled Resource Consumption (CWE-400) vulnerability in Linux Linux Kernel. Its CVSS base score is 8.1 (High).

Operationally, ranked at the 15.3th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

In the Linux kernel, the following vulnerability has been resolved: enetc: Fix illegal access when reading affinity_hint irq_set_affinity_hit() stores a reference to the cpumask_t parameter in the irq descriptor, and that reference can be accessed later from irq_affinity_hint_proc_show(). Since the…

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cpu_mask parameter passed to irq_set_affinity_hit() has only temporary storage (it's on the stack memory), later accesses to it are illegal. Thus reads from the corresponding procfs affinity_hint file can result in paging request oops. The issue is fixed by the get_cpu_mask() helper, which provides a permanent storage for the cpumask_t parameter.

CWE(s)

Related Threats

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

Affected Assets

linux
linux kernel
5.15 · 5.1 — 5.4.150 · 5.5 — 5.10.70 · 5.11 — 5.14.9

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