CVE intelligence and bounded remediation

CVE-2021-0272 — Juniper Junos security vulnerability

Medium CVSS 6.5

A kernel memory leak in QFX10002-32Q, QFX10002-60C, QFX10002-72Q, QFX10008, QFX10016 devices Flexible PIC Concentrators (FPCs) on Juniper Networks Junos OS allows an attacker to send genuine packets destined to the device to cause a Denial of Service (DoS) to the device. On QFX10002-32Q, QFX10002-60C, QFX10002-72Q devices the device will crash and restart. On QFX10008, QFX10016 devices, depending on the number of FPCs involved in an attack, one more more FPCs may crash and traffic through the device may be degraded in other ways, until the attack traffic stops. A reboot is required to restore service and clear the kernel memory. Continued receipt and processing of these genuine packets will create a sustained Denial of Service (DoS) condition. On QFX10008, QFX10016 devices, an indicator of compromise may be the existence of DCPFE core files. You can also monitor PFE memory utilization for incremental growth: user@qfx-RE:0% cprod -A fpc0 -c "show heap 0" | grep -i ke 0 3788a1b0 3221225048 2417120656 804104392 24 Kernel user@qfx-RE:0% cprod -A fpc0 -c "show heap 0" | grep -i ke 0 3788a1b0 3221225048 2332332200 888892848 27 Kernel This issue affects: Juniper Networks Junos OS on QFX1…

Severity
Medium
CVSS
6.5 (3.1)
Published
2021-04-22
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-401

Affected products

  • juniper / junos / 16.1

Showing 1 representative product identities from 235 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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