An incorrect permission assignment vulnerability in the PostgreSQL commands of the Zyxel USG FLEX H series uOS firmware versions from V1.20
An incorrect permission assignment vulnerability in the PostgreSQL commands of the Zyxel USG FLEX H series uOS firmware versions from V1.20 through V1.31 could allow an authenticated local attacker with low privileges to gain access to the Linux shell and escalate their privileges by crafting malicious scripts or modifying system configurations with administrator-level access through a stolen token. Modifying the system configuration is only possible if the administrator has not logged out and the token remains valid.
- Published
- Apr 21, 2025
- Updated
- Jun 17, 2026
- EPSS
- 0.9% · 60th percentile
- CWE
- CWE-732
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Report tools
Action score
31
Monitor
Low priority for now.
- CVSS
- 31 / 40 · 7.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.9%
CISA SSVC decision
- Exploitation
- proof of concept
- Automatable
- no
- Technical impact
- total
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · Zyxel
- 7.8
- 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.
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 helpAffected systems
| 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 uos1.20 and later · before 1.32
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
- from V1.20 through V1.31affected
Same product
zyxel: all recordsOther highest-scoring records for the same primary product.
- CVE-2024-9677The insufficiently protected credentials vulnerability in the CLI command of the USG FLEX H series uOS firmware version V1.21 and earlier ve31Monitor
- CVE-2025-1732An improper privilege management vulnerability in the recovery function of the Zyxel USG FLEX H series uOS firmware version V1.31 and earlie26Monitor
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
Proof of concept available
A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.
Evidence
- Exploit-DB entry ×1
Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.
| Source | Kind | Date |
|---|---|---|
| Exploit-DB entry | local | 2025-05-18 |
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.
- Published
- First PoC+26 d
- TodayOct 5, 2026+532 d
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.
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.
- 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
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-732 · Incorrect Permission Assignment for Critical ResourceCVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
nvd-secondary
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)
- Accessing Functionality Not Properly Constrained by ACLsCAPEC-1likelihood: High · High
- Privilege AbuseCAPEC-122likelihood: High · Medium
- Directory IndexingCAPEC-127likelihood: High · Medium
- Using Malicious FilesCAPEC-17likelihood: High · Very High
- Exploiting Incorrectly Configured Access Control Security LevelsCAPEC-180likelihood: High · Medium
- Signing Malicious CodeCAPEC-206Very High
- Hijacking a privileged processCAPEC-234Medium
- Reusing Session IDs (aka Session Replay)CAPEC-60likelihood: High · High
ATT&CK techniques
- File and Directory DiscoveryT1083
- Access Token Manipulation:Token Impersonation/TheftT1134.001
- Server Software Component: Terminal Services DLLT1505.005
- Abuse Elevation Control MechanismT1548
- Use Alternate Authentication Material:Web Session CookieT1550.004
- Subvert Trust Controls:Code SigningT1553.002
- Compromise Client Software BinaryT1554
- Hijack Execution Flow:Executable Installer File Permissions WeaknessT1574.005
- Hijack Execution Flow: ServicesFile Permissions WeaknessT1574.010
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
- seclists.org/fulldisclosure/2025/Apr/27
Vendor advisories and official records. Exploit/PoC links are deliberately left out.