CVE intelligence and bounded remediation

CVE-2021-0222 — Juniper Junos security vulnerability

High CVSS 7.4

A vulnerability in Juniper Networks Junos OS allows an attacker to cause a Denial of Service (DoS) to the device by sending certain crafted protocol packets from an adjacent device with invalid payloads to the device. These crafted packets, which should be discarded, are instead replicated and sent to the RE. Over time, a Denial of Service (DoS) occurs. Continued receipt of these crafted protocol packets will cause an extended Denial of Service (DoS) condition, which may cause wider traffic impact due to protocol flapping. An indication of compromise is to check "monitor interface traffic" on the ingress and egress port packet counts. For each ingress packet, two duplicate packets are seen on egress. This issue can be triggered by IPv4 and IPv6 packets. This issue affects all traffic through the device. This issue affects: Juniper Networks Junos OS: 14.1X53 versions prior to 14.1X53-D53 on EX4300, QFX3500, QFX5100, EX4600; 15.1 versions prior to 15.1R7-S6 on EX4300, QFX3500, QFX5100, EX4600; 16.1 versions prior to 16.1R7-S7 on EX4300, QFX5100, EX4600; 17.1 versions prior to 17.1R2-S11 on EX4300, QFX5100, EX4600; 17.1 versions prior to 117.1R3-S2 on EX4300; 17.2 versions prior to 1…

Severity
High
CVSS
7.4 (3.1)
Published
2021-01-15
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-16

Affected products

  • juniper / junos / 14.1x53

Showing 1 representative product identities from 245 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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