Cyber Resilience

CVE-2024-21604

HighDDoS

Published: 12 January 2024

Published
12 January 2024
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 0.0029 52.4th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2024-21604 is a high-severity Allocation of Resources Without Limits or Throttling (CWE-770) vulnerability in Juniper Junos Os Evolved. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Direct Network Flood (T1498.001); ranked in the top 47.6% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

An Allocation of Resources Without Limits or Throttling vulnerability in the kernel of Juniper Networks Junos OS Evolved allows an unauthenticated, network-based attacker to cause a Denial of Service (DoS). If a high rate of specific valid packets are processed…

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by the routing engine (RE) this will lead to a loss of connectivity of the RE with other components of the chassis and thereby a complete and persistent system outage. Please note that a carefully designed lo0 firewall filter will block or limit these packets which should prevent this issue from occurring. The following log messages can be seen when this issue occurs: <host> kernel: nf_conntrack: nf_conntrack: table full, dropping packet This issue affects Juniper Networks Junos OS Evolved: * All versions earlier than 20.4R3-S7-EVO; * 21.2R1-EVO and later versions; * 21.4-EVO versions earlier than 21.4R3-S5-EVO; * 22.1-EVO versions earlier than 22.1R3-S2-EVO; * 22.2-EVO versions earlier than 22.2R3-EVO; * 22.3-EVO versions earlier than 22.3R2-EVO; * 22.4-EVO versions earlier than 22.4R2-EVO.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1498.001 Direct Network Flood Impact
Adversaries may attempt to cause a denial of service (DoS) by directly sending a high-volume of network traffic to a target.
Why these techniques?

CVE-2024-21604 enables unauthenticated network-based DoS via high-rate flooding of specific valid packets exhausting the nf_conntrack table in the Junos OS Evolved kernel, causing persistent system outage (Direct Network Flood).

Affected Assets

juniper
junos os evolved
21.2, 21.4, 22.1, 22.2, 22.3

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