CVE intelligence and bounded remediation

CVE-2024-39529 — Juniper Junos security vulnerability

High CVSS 8.7

A Use of Externally-Controlled Format String vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on SRX Series allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS). If DNS Domain Generation Algorithm (DGA) detection or tunnel detection, and DNS-filtering traceoptions are configured, and specific valid transit DNS traffic is received this causes a PFE crash and restart, leading to a Denial of Service. This issue affects Junos OS: * All versions before 21.4R3-S6, * 22.2 versions before 22.2R3-S3, * 22.3 versions before 22.3R3-S3, * 22.4 versions before 22.4R3, * 23.2 versions before 23.2R2.

Severity
High
CVSS
8.7 (4.0)
Published
2024-07-11
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-134

Affected products

  • juniper / junos
  • juniper / junos / 21.4

Showing 2 representative product identities from 45 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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