CVE intelligence and bounded remediation

CVE-2024-39561 — Juniper Junos security vulnerability

Medium CVSS 6.9

An Improper Check for Unusual or Exceptional Conditions vulnerability in the flow daemon (flowd) of Juniper Networks Junos OS on SRX4600 and SRX5000 Series allows an attacker to send TCP packets with SYN/FIN or SYN/RST flags, bypassing the expected blocking of these packets. A TCP packet with SYN/FIN or SYN/RST should be dropped in flowd. However, when no-syn-check and Express Path are enabled, these TCP packets are unexpectedly transferred to the downstream network. This issue affects Junos OS on SRX4600 and SRX5000 Series: * All versions before 21.2R3-S8, * from 21.4 before 21.4R3-S7, * from 22.1 before 22.1R3-S6, * from 22.2 before 22.2R3-S4, * from 22.3 before 22.3R3-S3, * from 22.4 before 22.4R3-S2, * from 23.2 before 23.2R2, * from 23.4 before 23.4R1-S1, 23.4R2.

Severity
Medium
CVSS
6.9 (4.0)
Published
2024-07-10
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-754

Affected products

  • juniper / junos
  • juniper / junos / 21.2

Showing 2 representative product identities from 79 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

General vulnerability remediation

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

Check exposure

  • Confirm the affected component, deployment paths, reachable interfaces, and enabled features from inventories and configuration, without probing production destructively.
  • Compare the advisory's affected conditions with the repository lockfiles, build manifests, artifacts, and runtime inventory.
  • Identify data sensitivity, trust boundaries, and privilege level for every confirmed affected deployment.

Remediate safely

  • Apply a vendor-supported fix or remove the affected component or feature; record the selected change and its source in the repository.
  • Update direct and transitive dependency locks, generated artifacts, deployment manifests, and asset inventories together.
  • Add a regression test for the documented unsafe condition using inert inputs and preserve rollback instructions.

Authoritative sources

Complete CVE record and remediation plan

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