CVE intelligence and bounded remediation

CVE-2020-3496 — Cisco Sg200-50 Firmware security vulnerability

Medium CVSS 5.3

A vulnerability in the IPv6 packet processing engine of Cisco Small Business Smart and Managed Switches could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to insufficient validation of incoming IPv6 traffic. An attacker could exploit this vulnerability by sending a crafted IPv6 packet through an affected device. A successful exploit could allow the attacker to cause the switch management CLI to stop responding, resulting in a DoS condition. This vulnerability is specific to IPv6 traffic. IPv4 traffic is not affected.

Severity
Medium
CVSS
5.3 (3.1)
Published
2020-08-26
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-20

Affected products

  • cisco / sg200-50_firmware
  • cisco / sg200-50p_firmware
  • cisco / sg200-50fp_firmware
  • cisco / sg200-26_firmware
  • cisco / sg200-26p_firmware
  • cisco / sg200-26fp_firmware

Showing 6 representative product identities from 114 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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