THREATPORT/VULNERABILITY/CVE-2025-9133
HIGH SEVERITY

CVE-2025-9133

Zld vulnerability

CVSS
8.1
EPSS
5.4%
EPSS pct
92th
Exploited
No known
A missing authorization vulnerability in Zyxel ATP series firmware versions from V4.32 through V5.40, USG FLEX series firmware versions from V4.50 through V5.40, USG FLEX 50(W) series firmware versions from V4.16 through V5.40, and USG20(W)-VPN series firmware versions from V4.16 through V5.40 could allow a semi-authenticated attacker—who has completed only the first stage of the two-factor authentication (2FA) process—to view and download the system configuration from an affected device.
Affected vendor
Zyxel
Affected product
Zld
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Weakness type (CWE)
Published
2025-10-21

Risk analysis

Based on its CVSS vector, this vulnerability is exploitable over the network, low attack complexity, requiring low privileges, no user interaction. Successful exploitation leads to high impact to confidentiality, high impact to integrity.

Its EPSS score of 5.4% reflects a lower probability of exploitation activity in the wild over the next 30 days, placing it above 92% of all scored CVEs.

Check your external exposure to CVE-2025-9133

  • Confirm whether Zyxel Zld is running on any internet-facing host or subdomain.
  • Match discovered service fingerprints against the version affected by CVE-2025-9133.
  • Prioritise remediation if the asset is public, business-critical, or near authentication/payment flows.

How ThreatPort helps with CVE-2025-9133

ThreatPort's external attack surface scanner checks your internet-facing assets — agentlessly, from the outside in — for the exposed services and versions that CVE-2025-9133 affects, then prioritises the finding by real risk using CISA KEV and FIRST.org EPSS.

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