dbcve.org
UosOperating system · Zyxel

CVE-2024-9677

HIGH · 7.8 CVSS v3.1 Published 2024-10-22
Fix available
A fix is available. Upgrade to 1.30 or later.
See remediation →
80/100
Remediation priority · High
Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
The insufficiently protected credentials vulnerability in the CLI command of the USG FLEX H series uOS firmware version V1.21 and earlier versions could allow an authenticated local attacker to gain privilege escalation by stealing the authentication token of a login administrator. Note that this attack could be successful only if the administrator has not logged out.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

The USG FLEX H series uOS firmware versions V1.21 and earlier contain an insufficiently protected credentials vulnerability in the CLI command interface. An authenticated local attacker can steal the authentication token of a currently logged-in administrator to achieve privilege escalation. This attack requires the administrator to still be logged in at the time of exploitation.

MitigationUpgrade USG FLEX H series firmware to a version beyond V1.21. Additionally, administrators should ensure they log out of CLI sessions when finished to prevent token theft.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
UosOperating system
Affected:< 1.30

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify device model
    Access the device management interface or use 'show system-info' CLI command to confirm the device is a USG FLEX H series model
    Affected if Device is not a USG FLEX H series - this vulnerability only affects that specific product line
  2. Check uOS firmware version
    Use the CLI command 'show version' or access the web management interface to view the installed uOS firmware version number
    Affected if Firmware version is V1.21 or earlier (versions prior to 1.30 are affected)
  3. Verify CLI interface status
    Confirm the CLI command interface is enabled and accessible on the device through management settings
    Affected if CLI interface is disabled - the vulnerability exists in the CLI command interface specifically
  4. Check for active administrator sessions
    Use 'show sessions' or 'show login users' CLI command to list currently logged-in administrator sessions
    Affected if One or more administrator sessions are active - the attack requires an administrator to still be logged in at time of exploitation

The environment is affected if the device is a USG FLEX H series running uOS firmware V1.21 or earlier with the CLI interface enabled AND an administrator session is currently active.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 1.30 or later
Fixed in 1.30
Interim mitigation

Upgrade USG FLEX H series firmware to a version beyond V1.21. Additionally, administrators should ensure they log out of CLI sessions when finished to prevent token theft.

Recommended fix Moderate confidence

uOS firmware version 1.30 or later

  1. 1. Identify the specific USG FLEX H series device model in your environment
  2. 2. Download the uOS firmware version 1.30 or later from Zyxel's official support website (www.zyxel.com)
  3. 3. Review the firmware release notes to confirm the security fix for CVE-2024-9677 is included
  4. 4. Back up the current device configuration
  5. 5. Upload and install the firmware version 1.30 or later via the device's web interface or CLI
  6. 6. Verify the upgrade was successful and the device is operational
  7. 7. After upgrading, ensure all administrators log out and log back in to obtain new authentication tokens
Caveat Review Zyxel release notes for any configuration or feature changes between your current version and 1.30; firmware upgrades may require reconfiguration of some settings

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Uos Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing6.0 h
  • Review / QA3.0 h
16.0 hours of engineering $2,760
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2024-9677 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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