CVE intelligence and bounded remediation

CVE-2021-0280 — Juniper Junos security vulnerability

High CVSS 7.5

Due to an Improper Initialization vulnerability in Juniper Networks Junos OS on PTX platforms and QFX10K Series with Paradise (PE) chipset-based line cards, ddos-protection configuration changes made from the CLI will not take effect as expected beyond the default DDoS (Distributed Denial of Service) settings in the Packet Forwarding Engine (PFE). This may cause BFD sessions to flap when a high rate of specific packets are received. Flapping of BFD sessions in turn may impact routing protocols and network stability, leading to a Denial of Service (DoS) condition. Continued receipt and processing of this packet will create a sustained Denial of Service (DoS) condition. This issue affects only the following platforms with Paradise (PE) chipset-based line cards: PTX1000, PTX3000 (NextGen), PTX5000, PTX10008, PTX10016 Series and QFX10002 Series. This issue affects: Juniper Networks Junos OS 17.4 versions prior to 17.4R3-S5 on PTX Series, QFX10K Series; 18.2 versions prior to 18.2R3-S8 on PTX Series, QFX10K Series; 18.3 versions prior to 18.3R3-S5 on PTX Series, QFX10K Series; 18.4 versions prior to 18.4R2-S8 on PTX Series, QFX10K Series; 19.1 versions prior to 19.1R3-S5 on PTX Series…

Severity
High
CVSS
7.5 (3.1)
Published
2021-07-15
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-665

Affected products

  • juniper / junos / 17.4

Showing 1 representative product identities from 153 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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