CVE intelligence and bounded remediation

CVE-2024-21595 — Juniper Junos security vulnerability

High CVSS 7.5

An Improper Validation of Syntactic Correctness of Input vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS allows a network-based, unauthenticated attacker to cause a Denial of Service (DoS). If an attacker sends high rate of specific ICMP traffic to a device with VXLAN configured, this causes a deadlock of the PFE and results in the device becoming unresponsive. A manual restart will be required to recover the device. This issue only affects EX4100, EX4400, EX4600, QFX5000 Series devices. This issue affects: Juniper Networks Junos OS * 21.4R3 versions earlier than 21.4R3-S4; * 22.1R3 versions earlier than 22.1R3-S3; * 22.2R2 versions earlier than 22.2R3-S1; * 22.3 versions earlier than 22.3R2-S2, 22.3R3; * 22.4 versions earlier than 22.4R2; * 23.1 versions earlier than 23.1R2.

Severity
High
CVSS
7.5 (3.1)
Published
2024-01-12
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-1286

Affected products

  • juniper / junos / 21.4
  • juniper / junos / 22.1
  • juniper / junos / 22.2
  • juniper / junos / 22.3

Showing 4 representative product identities from 22 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Resource exhaustion and denial of service

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Identify attacker-influenced work factors including input size, nesting, compression, fan-out, regex cost, allocation, recursion, retries, and connection lifetime.
  • Map per-request and shared CPU, memory, disk, descriptor, thread, queue, and downstream-service limits.
  • Determine whether authentication, tenancy, quotas, and rate controls apply before expensive processing begins.

Remediate safely

  • Bound input size, nesting, expansion, work, concurrency, queue depth, retries, and execution time before resource-intensive processing.
  • Release resources on every success, error, cancellation, and timeout path and use backpressure instead of unbounded buffering.
  • Update affected components and add small deterministic tests that assert resource ceilings rather than exhausting a host.

Authoritative sources

Complete CVE record and remediation plan

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