NVD / CVE Program· CNA Zyxel

CVE-2025-1732: An improper privilege management vulnerability in the recovery function of the Zyxel USG FLEX H series uOS firmware version V1.31 and earlie

Noroxi assessment

Priority: Monitor (action score 26/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.20% (FIRST EPSS).
Someone with local access to the system can trigger it. Administrator privileges are required. No user action is required. No special conditions are required; it is repeatable.
According to the record, no fixed version is available yet.

Low priority for now. Update when a fix is released; follow the vendor's advisory.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

An improper privilege management vulnerability in the recovery function of the Zyxel USG FLEX H series uOS firmware version V1.31 and earlier could allow an authenticated local attacker with administrator privileges to upload a crafted configuration file and escalate privileges on a vulnerable device.

MediumCVSS 6.7 · v3.1—No exploit No fix recorded

Local privilege escalation

Published: Apr 21, 2025
Updated: Jun 17, 2026
EPSS: 0.2% · 10th percentile
CWE: CWE-269

Report tools

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Action score

Monitor

Low priority for now.

CVSS: 26 / 40 · 6.7 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.2%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · Zyxel: 6.7; NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
No fixed version yet

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
zyxel	uos	cpe:2.3:o:zyxel:uos
zyxel	usg flex 100h	cpe:2.3:h:zyxel:usg_flex_100h
zyxel	usg flex 100hp	cpe:2.3:h:zyxel:usg_flex_100hp
zyxel	usg flex 200h	cpe:2.3:h:zyxel:usg_flex_200h
zyxel	usg flex 200hp	cpe:2.3:h:zyxel:usg_flex_200hp
zyxel	usg flex 500h	cpe:2.3:h:zyxel:usg_flex_500h
zyxel	usg flex 50h	cpe:2.3:h:zyxel:usg_flex_50h
zyxel	usg flex 50hp	cpe:2.3:h:zyxel:usg_flex_50hp
zyxel	usg flex 700h	cpe:2.3:h:zyxel:usg_flex_700h

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

zyxel uos1.31

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Zyxel). Independent of NVD's CPE analysis and usually ahead of it.

Zyxel USG FLEX H series uOS firmware
- <= V1.31affected

Same product

zyxel: all records

Other highest-scoring records for the same primary product.

CVE-2025-1731An incorrect permission assignment vulnerability in the PostgreSQL commands of the Zyxel USG FLEX H series uOS firmware versions from V1.20
31Monitor
CVE-2024-9677The insufficiently protected credentials vulnerability in the CLI command of the USG FLEX H series uOS firmware version V1.21 and earlier ve
31Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

Someone with local access to the system can trigger it.
Administrator privileges are required.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: high · data can be read
Integrity: high · data or configuration can be modified
Availability: high · the service can be disrupted

Attack vector: Local
Attack complexity: Low
Privileges required: High
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: High

Weakness class (CWE)

CWE-269 · Improper Privilege Management

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

nvd-secondary

Root cause

To simplify setup, a service account is granted broad, cluster-wide permissions. The principle of least privilege is skipped during installation.

The bug in code

The whole CWE-269 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

yaml

1kind: ClusterRole
2rules:
3  - apiGroups: ["*"]
4    resources: ["*"]
5    verbs: ["*"]

Fixed

yaml

1kind: Role
2metadata:
3  namespace: lodos-system
4rules:
5  - apiGroups: ["apps"]
6    resources: ["deployments"]
7    verbs: ["get", "list", "update"]

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Attack patterns (CAPEC)

ATT&CK techniques

Abuse Elevation Control MechanismT1548

Change log

No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.

References

www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-incorrect-permission-assignment-and-improper-privilege-management-vulnerabilities-in-usg-flex-h-series-firewalls-04-22-2025

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records