CVE intelligence and bounded remediation

CVE-2019-12583 — Zyxel Uag2100 Firmware security vulnerability

Critical CVSS 9.1

Missing Access Control in the "Free Time" component of several Zyxel UAG, USG, and ZyWall devices allows a remote attacker to generate guest accounts by directly accessing the account generator. This can lead to unauthorised network access or Denial of Service.

Severity
Critical
CVSS
9.1 (3.0)
Published
2019-06-27
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-425

Affected products

  • zyxel / uag2100_firmware
  • zyxel / uag4100_firmware
  • zyxel / uag5100_firmware
  • zyxel / usg110_firmware
  • zyxel / usg210_firmware
  • zyxel / usg310_firmware

Showing 6 representative product identities from 14 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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