CVE intelligence and bounded remediation

CVE-2020-3527 — Cisco Ios Xe security vulnerability

High CVSS 8.6

A vulnerability in the Polaris kernel of Cisco Catalyst 9200 Series Switches could allow an unauthenticated, remote attacker to crash the device. The vulnerability is due to insufficient packet size validation. An attacker could exploit this vulnerability by sending jumbo frames or frames larger than the configured MTU size to the management interface of this device. A successful exploit could allow the attacker to crash the device fully before an automatic recovery.

Severity
High
CVSS
8.6 (3.1)
Published
2020-09-24
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-20, CWE-400

Affected products

  • cisco / ios_xe

Showing 1 representative product identities from 2 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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