CVE intelligence and bounded remediation

CVE-2023-36840 — Juniper Junos security vulnerability

Medium CVSS 5.5

A Reachable Assertion vulnerability in Routing Protocol Daemon (RPD) of Juniper Networks Junos OS and Junos OS Evolved allows a locally-based, low-privileged attacker to cause a Denial of Service (DoS). On all Junos OS and Junos OS Evolved, when a specific L2VPN command is run, RPD will crash and restart. Continued execution of this specific command will create a sustained Denial of Service (DoS) condition. This issue affects: Juniper Networks Junos OS All versions prior to 19.3R3-S10; 20.1 versions prior to 20.1R3-S4; 20.2 versions prior to 20.2R3-S6; 20.3 versions prior to 20.3R3-S6; 20.4 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-S2; 21.4 versions prior to 21.4R3; 22.1 versions prior to 22.1R3; 22.2 versions prior to 22.2R2; 22.3 versions prior to 22.3R2; Juniper Networks Junos OS Evolved All versions prior to 20.4R3-S7-EVO; 21.1 versions prior to 21.1R3-S3-EVO; 21.2 versions prior to 21.2R3-S5-EVO; 21.3 versions prior to 21.3R3-S4-EVO; 21.4 versions prior to 21.4R3-EVO; 22.1 versions prior to 22.1R3-EVO; 22.2 versions prior to 22.2R2-EVO; 22.3 versions prior to 22.3R2-EVO;

Severity
Medium
CVSS
5.5 (3.1)
Published
2023-07-14
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-617

Affected products

  • juniper / junos
  • juniper / junos / 19.3

Showing 2 representative product identities from 204 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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