CVE intelligence and bounded remediation

CVE-2020-3508 — Cisco Ios Xe security vulnerability

High CVSS 7.4

A vulnerability in the IP Address Resolution Protocol (ARP) feature of Cisco IOS XE Software for Cisco ASR 1000 Series Aggregation Services Routers with a 20-Gbps Embedded Services Processor (ESP) installed could allow an unauthenticated, adjacent attacker to cause an affected device to reload, resulting in a denial of service condition. The vulnerability is due to insufficient error handling when an affected device has reached platform limitations. An attacker could exploit this vulnerability by sending a malicious series of IP ARP messages to an affected device. A successful exploit could allow the attacker to exhaust system resources, which would eventually cause the affected device to reload.

Severity
High
CVSS
7.4 (3.1)
Published
2020-09-24
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-400

Affected products

  • cisco / ios_xe / 16.3.1
  • cisco / ios_xe / 16.6.5
  • cisco / ios_xe / 16.7(1)
  • cisco / ios_xe / 17.1.1
  • cisco / ios_xe / 16.9.1
  • cisco / ios_xe / 17.4.1

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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