CVE-2023-50921
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 · uneditedAn issue was discovered on GL.iNet devices through 4.5.0. Attackers can invoke the add_user interface in the system module to gain root privileges. This affects A1300 4.4.6, AX1800 4.4.6, AXT1800 4.4.6, MT3000 4.4.6, MT2500 4.4.6, MT6000 4.5.0, MT1300 4.3.7, MT300N-V2 4.3.7, AR750S 4.3.7, AR750 4.3.7, AR300M 4.3.7, and B1300 4.3.7.
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 confidenceUnauthenticated or low-privilege attackers can invoke the add_user function in the system module on GL.iNet routers to create new administrative accounts with root privileges, achieving full device compromise.
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= 4.3.7= 4.3.7= 4.3.7= 4.3.7= 4.3.7= 4.3.7= 4.5.0= 4.4.6CVSS 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
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/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 checksWork through these to decide whether this CVE applies to you.
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Identify router model and firmware versionAccess the router admin interface (typically at 192.168.8.1) and navigate to System > Overview or Status page to view the device model and firmware version. Alternatively, check the /etc/os-release file or run 'cat /proc/cpuinfo' via SSH if available.Affected if The firmware version matches exactly 4.3.7, 4.4.6, or 4.5.0 for the listed models (GL-MT1300, GL-MT300N V2, GL-AR750S, GL-AR750, GL-AR300M, GL-B1300, GL-MT6000, GL-A1300).
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Check for unauthorized admin accountsAccess the router admin interface and navigate to Administration > User Management or similar. Look for any unexpected administrator accounts beyond the default admin account. Alternatively, examine /etc/passwd or /etc/shadow files via SSH for new users with root-level privileges.Affected if There are admin or root-level user accounts that were not created by the legitimate administrator.
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Verify system module add_user function exposureIf the router has an API endpoint accessible (typically at /api/system/add_user or similar), attempt to identify if unauthenticated or low-privilege access to user creation functions is possible through direct API calls. Check router logs in /var/log/ for entries indicating unauthorized add_user invocations.Affected if The add_user function in the system module is accessible without proper authentication or from untrusted networks.
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Review admin interface access controlsCheck the router's firewall settings and access control lists (typically under Network > Firewall or Administration > Access Control) to determine if the admin interface is exposed to WAN or untrusted networks.Affected if The admin web interface (port 80/443) is reachable from WAN or untrusted network segments.
A user is affected if they are running one of the listed GL.iNet router models on firmware versions 4.3.7, 4.4.6, or 4.5.0 and the admin interface is accessible from networks beyond the trusted local network.
Generated from the published advisory. Verify against your own configuration.
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 · scopedUpdate firmware to a version beyond 4.5.0 when released by GL.iNet; until then, restrict administrative interface access to trusted networks only.
MT6000: upgrade to 4.5.1 or later; A1300: upgrade to 4.4.7 or later; all other affected models (MT1300, MT300N-V2, AR750S, AR750, AR300M, B1300): upgrade to the latest available firmware version after 4.3.7
- 1. Identify your exact GL.iNet device model from the affected list (Mt1300, Mt300n V2, Ar750s, Ar750, Ar300m, B1300, Mt6000, A1300)
- 2. Check the current firmware version installed on your device through the admin web interface or GL.iNet mobile app
- 3. Visit the official GL.iNet firmware download page at https://www.gl-inet.com/firmware/ and locate your specific device model
- 4. Download the latest available firmware for your device - the vulnerability is fixed in versions after 4.5.0 for MT6000 and after 4.4.6 for A1300 and other devices
- 5. Access your router's admin panel, navigate to the Firmware Upgrade section
- 6. Upload and install the latest firmware version, ensuring continuous power during the update process
- 7. After reboot, verify the new firmware version is installed and confirm the add_user functionality no longer allows unauthorized privilege escalation
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation3.0 h
- Implementation6.0 h
- Testing3.0 h
- Review / QA2.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2023-50921 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2023-50921 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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