CVE intelligence and bounded remediation

CVE-2024-39554 — Juniper Junos security vulnerability

High CVSS 8.2

A Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') vulnerability the Routing Protocol Daemon (rpd) of Juniper Networks Junos OS and Juniper Networks Junos OS Evolved allows an unauthenticated, network-based attacker to inject incremental routing updates when BGP multipath is enabled, causing rpd to crash and restart, resulting in a Denial of Service (DoS). Since this is a timing issue (race condition), the successful exploitation of this vulnerability is outside the attacker's control. However, continued receipt and processing of this packet may create a sustained Denial of Service (DoS) condition. On all Junos OS and Junos OS Evolved platforms with BGP multipath enabled, a specific multipath calculation removes the original next hop from the multipath lead routes nexthop-set. When this change happens, multipath relies on certain internal timing to record the update. Under certain circumstance and with specific timing, this could result in an rpd crash. This issue only affects systems with BGP multipath enabled. This issue affects: Junos OS: * All versions of 21.1 * from 21.2 before 21.2R3-S7, * from 21.4 before 21.4R3-S6, * from 22.1 bef…

Severity
High
CVSS
8.2 (4.0)
Published
2024-07-10
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-362

Affected products

  • juniper / junos
  • juniper / junos / 21.2

Showing 2 representative product identities from 125 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Race condition, TOCTOU, and lifecycle synchronization

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

Check exposure

  • Map concurrent actors, shared state, lock boundaries, signals, callbacks, retries, and check-then-use sequences in the affected path.
  • Determine whether untrusted users can influence timing, object names, filesystem state, or repeated state transitions.
  • Identify clustered and multi-process behavior that repository-local tests may not represent.

Remediate safely

  • Make the sensitive state transition atomic or protect it with a consistently ordered synchronization primitive.
  • Perform authorization and invariant checks on the same authoritative object and transaction used for the operation.
  • Use unique private resources, safe ownership transfer, and idempotent operations; add deterministic concurrency regression tests.

Authoritative sources

Complete CVE record and remediation plan

The detailed catalog view below loads this exact record, its source evidence, and the full seven-phase agentic change plan.