CVE intelligence and bounded remediation

CVE-2023-44203 — Juniper Junos security vulnerability

Medium CVSS 6.5

An Improper Check or Handling of Exceptional Conditions vulnerability in the Packet Forwarding Engine (pfe) of Juniper Networks Junos OS on QFX5000 Series, EX2300, EX3400, EX4100, EX4400 and EX4600 allows a adjacent attacker to send specific traffic, which leads to packet flooding, resulting in a Denial of Service (DoS). When a specific IGMP packet is received in an isolated VLAN, it is duplicated to all other ports under the primary VLAN, which causes a flood. This issue affects QFX5000 series, EX2300, EX3400, EX4100, EX4400 and EX4600 platforms only. This issue affects Juniper Junos OS on on QFX5000 Series, EX2300, EX3400, EX4100, EX4400 and EX4600: * All versions prior to 20.4R3-S5; * 21.1 versions prior to 21.1R3-S4; * 21.2 versions prior to 21.2R3-S3; * 21.3 versions prior to 21.3R3-S5; * 21.4 versions prior to 21.4R3-S2; * 22.1 versions prior to 22.1R3; * 22.2 versions prior to 22.2R3; * 22.3 versions prior to 22.3R2.

Severity
Medium
CVSS
6.5 (3.1)
Published
2023-10-13
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-703

Affected products

  • juniper / junos
  • juniper / junos / 20.4

Showing 2 representative product identities from 68 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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