CVE intelligence and bounded remediation

CVE-2021-43662 — Totolink Ex300 V2 Firmware security vulnerability

Medium CVSS 6.5

totolink EX300_v2, ver V4.0.3c.140_B20210429 and A720R ,ver V4.1.5cu.470_B20200911 have an issue which causes uncontrolled resource consumption.

Severity
Medium
CVSS
6.5 (3.1)
Published
2022-03-31
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-770

Affected products

  • totolink / ex300_v2_firmware / 4.0.3c.140_b20210429
  • totolink / a720r_firmware / 4.1.5cu.470_b20200911

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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