CVE intelligence and bounded remediation

CVE-2024-39526 — Juniper Junos Os Evolved security vulnerability

High CVSS 7.1

An Improper Handling of Exceptional Conditions vulnerability in packet processing of Juniper Networks Junos OS on MX Series with MPC10/MPC11/LC9600 line cards, EX9200 with EX9200-15C lines cards, MX304 devices, and Juniper Networks Junos OS Evolved on PTX Series, allows an attacker sending malformed DHCP packets to cause ingress packet processing to stop, leading to a Denial of Service (DoS). Continued receipt and processing of these packets will create a sustained Denial of Service (DoS) condition. This issue only occurs if DHCP snooping is enabled. See configuration below. This issue can be detected using following commands. Their output will display the interface status going down: user@device>show interfaces <if--x/x/x> user@device>show log messages | match <if--x/x/x> user@device>show log messages ==> will display the "[Error] Wedge-Detect : Host Loopback Wedge Detected: PFE: no," logs. This issue affects: Junos OS on MX Series with MPC10/MPC11/LC9600 line cards, EX9200 with EX9200-15C line cards, and MX304: * All versions before 21.2R3-S7, * from 21.4 before 21.4R3-S6, * from 22.2 before 22.2R3-S3, * all versions of 22.3, * from 22.4 before 22.4R3, * from 23.2 before 23.2R2…

Severity
High
CVSS
7.1 (4.0)
Published
2024-10-11
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-755

Affected products

  • juniper / junos_os_evolved
  • juniper / junos_os_evolved / 19.3
  • juniper / junos_os_evolved / 21.2

Showing 3 representative product identities from 138 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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