An improper privilege management vulnerability in the hotspot feature of the Zyxel USG FLEX series firmware versions 4.50 through 5.37 and V
An improper privilege management vulnerability in the hotspot feature of the Zyxel USG FLEX series firmware versions 4.50 through 5.37 and VPN series firmware versions 4.30 through 5.37 could allow an authenticated local attacker to access the system files on an affected device.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for help- Published
- Nov 27, 2023
- Updated
- Jun 17, 2026
- EPSS
- 0.2% · 11th percentile
- CWE
- CWE-269
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Report tools
Action score
22
Monitor
Low priority for now.
- CVSS
- 22 / 40 · 5.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.2%
CNA vs NVD score
- NVD
- —
- CNA · Zyxel
- 5.5
- 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.
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| zyxel | zld | cpe:2.3:o:zyxel:zld |
| zyxel | usg flex 100 | cpe:2.3:h:zyxel:usg_flex_100 |
| zyxel | usg flex 100w | cpe:2.3:h:zyxel:usg_flex_100w |
| zyxel | usg flex 200 | cpe:2.3:h:zyxel:usg_flex_200 |
| zyxel | usg flex 50 | cpe:2.3:h:zyxel:usg_flex_50 |
| zyxel | usg flex 500 | cpe:2.3:h:zyxel:usg_flex_500 |
| zyxel | usg flex 50w | cpe:2.3:h:zyxel:usg_flex_50w |
| zyxel | usg flex 700 | cpe:2.3:h:zyxel:usg_flex_700 |
| zyxel | vpn100 | cpe:2.3:h:zyxel:vpn100 |
| zyxel | vpn1000 | cpe:2.3:h:zyxel:vpn1000 |
| zyxel | vpn300 | cpe:2.3:h:zyxel:vpn300 |
| zyxel | vpn50 | cpe:2.3:h:zyxel:vpn50 |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- zyxel zld4.50 and later · up to 5.37 inclusive
- zyxel zld4.30 and later · up to 5.37 inclusive
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 series firmware
- versions 4.50 through 5.37affected
Zyxel VPN series firmware
- versions 4.30 through 5.37affected
Same product
zyxel: all recordsOther highest-scoring records for the same primary product.
- CVE-2024-11667A directory traversal vulnerability in the web management interface of Zyxel ATP series firmware versions V5.00 through V5.38, USG FLEX seriKEV70This week
- CVE-2020-25014A stack-based buffer overflow in fbwifi_continue.cgi on Zyxel UTM and VPN series of gateways running firmware version V4.30 through to V4.5540Plan
- CVE-2025-9133A missing authorization vulnerability in Zyxel ATP series firmware versions from V4.32 through V5.40, USG FLEX series firmware versions from34Monitor
- CVE-2024-42057A command injection vulnerability in the IPSec VPN feature of Zyxel ATP series firmware versions from V4.32 through V5.38, USG FLEX series f32Monitor
- CVE-2024-42058A null pointer dereference vulnerability in Zyxel ATP series firmware versions from V4.32 through V5.38, USG FLEX series firmware versions f30Monitor
- CVE-2023-4398An integer overflow vulnerability in the source code of the QuickSec IPSec toolkit used in the VPN feature of the Zyxel ATP series firmware 30Monitor
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.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
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 researchersFinders, 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.
- CVE-2023-379250 days apartAn improper privilege management vulnerability in the debug CLI command of the Zyxel ATP series firmware versions 4.32 through 5.37, USG FLE22Monitor
- CVE-2023-56500 days apartAn improper privilege management vulnerability in the ZySH of the Zyxel ATP series firmware versions 4.32 through 5.37, USG FLEX series firm22Monitor
- CVE-2023-57970 days apartAn improper privilege management vulnerability in the debug CLI command of the Zyxel ATP series firmware versions 4.32 through 5.37, USG FLE22Monitor
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.
- A low-privileged account is enough.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- none
- Availability
- none
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- None
- Availability impact
- None
Weakness class (CWE)
CWE-269 · Improper Privilege ManagementCVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
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 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
kind: ClusterRolerules: - apiGroups: ["*"] resources: ["*"] verbs: ["*"]Fixed
kind: Rolemetadata: namespace: lodos-systemrules: - apiGroups: ["apps"] resources: ["deployments"] 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.
Change log
No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.
References
Vendor advisories and official records. Exploit/PoC links are deliberately left out.