CVE intelligence and bounded remediation

CVE-2021-0285 — Juniper Junos security vulnerability

High CVSS 7.5

An uncontrolled resource consumption vulnerability in Juniper Networks Junos OS on QFX5000 Series and EX4600 Series switches allows an attacker sending large amounts of legitimate traffic destined to the device to cause Interchassis Control Protocol (ICCP) interruptions, leading to an unstable control connection between the Multi-Chassis Link Aggregation Group (MC-LAG) nodes which can in turn lead to traffic loss. Continued receipt of this amount of traffic will create a sustained Denial of Service (DoS) condition. An indication that the system could be impacted by this issue is the following log message: "DDOS_PROTOCOL_VIOLATION_SET: Warning: Host-bound traffic for protocol/exception LOCALNH:aggregate exceeded its allowed bandwidth at fpc <fpc number> for <n> times, started at <timestamp>" This issue affects Juniper Networks Junos OS on QFX5000 Series and EX4600 Series: 15.1 versions prior to 15.1R7-S9; 17.3 versions prior to 17.3R3-S11; 17.4 versions prior to 17.4R2-S13, 17.4R3-S5; 18.3 versions prior to 18.3R3-S5; 18.4 versions prior to 18.4R2-S8, 18.4R3-S7; 19.1 versions prior to 19.1R3-S5; 19.2 versions prior to 19.2R1-S6, 19.2R3-S2; 19.3 versions prior to 19.3R2-S6, 19.3R3-S…

Severity
High
CVSS
7.5 (3.1)
Published
2021-07-15
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-770, CWE-400

Affected products

  • juniper / junos / 15.1

Showing 1 representative product identities from 210 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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