Lte3202 M437 FirmwareOperating system · Zyxel

CVE-2022-43389

CRITICAL · 9.8 CVSS v3.1 Published 2023-01-11

Fix available

A fix is available. Upgrade to 1.00 / 1.15 or later.

See remediation →

100/100

Remediation priority · Urgent

Remotely reachable No privileges Zero-click

Official description

NVD · unedited

A buffer overflow vulnerability in the library of the web server in Zyxel NR7101 firmware prior to V1.15(ACCC.3)C0, which could allow an unauthenticated attacker to execute some OS commands or to cause denial-of-service (DoS) conditions on a vulnerable device.

Technical summary

dbcve analysis · moderate confidence

A buffer overflow vulnerability exists in the web server library of Zyxel NR7101 cellular router firmware prior to V1.15(ACCC.3)C0. The flaw allows unauthenticated remote attackers to potentially execute arbitrary OS commands or cause denial-of-service conditions on the vulnerable device.

MitigationUpgrade Zyxel NR7101 firmware to version V1.15(ACCC.3)C0 or later to remediate this vulnerability.

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

Affected products & versions

NVD · CPE data

Lte3202 M437 FirmwareOperating system

Affected:< 1.00$abwf.1$c0

Lte3316 M604 FirmwareOperating system

Affected:< 2.00$abmp.6$c0

Lte7480 M804 FirmwareOperating system

Affected:< 1.00$abra.6$c0

Lte7490 M904 FirmwareOperating system

Affected:< 1.00$abqy.5$c0

Nebula Fwa510 FirmwareOperating system

Affected:< 1.15$acgd.3$c0

Nebula Fwa710 FirmwareOperating system

Affected:< 1.15$acgc.3$c0

Nebula Nr7101 FirmwareOperating system

Affected:< 1.15$accc.3$c0

Nr5103 FirmwareOperating system

Affected:< 4.19$abyc.3$c0

CVSS breakdown

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?

dbcve checks

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

Identify device model

Access the device admin interface or check the device label to determine the exact model (e.g., NR7101, LTE3202, etc.)

Affected if The device is one of the affected models: LTE3202 M437, LTE3316 M604, LTE7480 M804, LTE7490 M904, Nebula Fwa510, Nebula Fwa710, Nebula Nr7101, or Nr5103
Check installed firmware version

Navigate to the device web interface Status or Administration page, or log in via SSH and run 'cat /proc/version' or 'ver' command to retrieve the firmware version string

Affected if The firmware version is lower than the specified threshold for your model (e.g., NR7101 < 1.15(accc.3)c0, LTE3202 < 1.00(abwf.1)c0, etc.)
Verify web server is accessible

Attempt to access the device web interface by entering the device IP address in a browser (http://<device-ip>). Check if the login page loads

Affected if The web interface is reachable from the network and the device firmware version is below the patched version
Confirm web server library is active

Check running processes via SSH or telnet: look for httpd, webs, or lighttpd processes. On some models, check /var/etc/httpd.conf or similar config files

Affected if A web server process is running and the firmware version is prior to the fixed release

A user is affected if they are running any of the listed Zyxel device models with firmware versions below the specified threshold and the web server interface is exposed on the network.

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

Remediation

dbcve · scoped

Upgrade available Upgrade to 1.00 / 1.15 / 2.00 or later

Fixed in 1.001.152.00

Interim mitigation

Upgrade Zyxel NR7101 firmware to version V1.15(ACCC.3)C0 or later to remediate this vulnerability.

Recommended fix High confidence

Upgrade to the firmware version specified for each model: 1.00(abwf.1)c0 for Lte3202 M437, 2.00(abmp.6)c0 for Lte3316 M604, 1.00(abra.6)c0 for Lte7480 M804, 1.00(abqy.5)c0 for Lte7490 M904, 1.15(acgd.3)c0 for Nebula Fwa510, 1.15(acgc.3)c0 for Nebula Fwa710, 1.15(accc.3)c0 for Nebula Nr7101, 4.19(aby

1. Identify the specific model number (M437, M604, M804, M904, Fwa510, Fwa710, Nr7101, or Nr5103) of the affected Zyxel device
2. Access the device's web-based management interface or administrative console
3. Navigate to the Firmware Upgrade or Administration section
4. Obtain the appropriate firmware file from Zyxel's official support website (support.zyxel.com) matching the specific model and version listed in the fixed version field
5. Upload the firmware file and initiate the upgrade process
6. Wait for the upgrade to complete and verify the device reboots successfully
7. Confirm the firmware version has been updated to the fixed version: Lte3202 M437 to 1.00(abwf.1)c0 | Lte3316 M604 to 2.00(abmp.6)c0 | Lte7480 M804 to 1.00(abra.6)c0 | Lte7490 M904 to 1.00(abqy.5)c0 | Nebula Fwa510 to 1.15(acgd.3)c0 | Nebula Fwa710 to 1.15(acgc.3)c0 | Nebula Nr7101 to 1.15(accc.3)c0 | Nr5103 to 4.19(abyc.3)c0

Caveat Firmware upgrades may temporarily disrupt network connectivity; ensure appropriate maintenance window and backup configuration

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

Fix this in Lte3202 M437 Firmware Scoped from the published advisory

Consultation3.0 h
Implementation4.0 h
Testing3.0 h
Review / QA2.0 h

12.0 hours of engineering $2,130

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Scan for this in your stack

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References

Primary sources

www.zyxel.comVendor Advisory
nvd.nist.govNVD record

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2022-43389 in production — separate from our analysis above.

Notes0 Guidelines

Know something about CVE-2022-43389?

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

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here

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
No spam, self-promotion, credentials, or personal data

At a glance

A fix existsUpgrade to 1.00 / 1.15 or later

Severity 9.8 Critical

Exploit likelihood EPSS, next 30 days 0.6%

Affects: Lte3202 M437 Firmware

Remediation

A high-priority fix

Fix this in Lte3202 M437 Firmware 12 hrs · Moderate

Typical engagement from $2,130

Get a fix See the full breakdown ↓

A high-priority vulnerability. Send your environment and a specialist will scope CVE-2022-43389 and return a fixed quote and timeline.

You’ll deal with our team directly and deploy the reviewed fix to staging first — never straight to production.

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.

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.

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.

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.

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.

Check your environment

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.

Scan for this in your stack

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Practitioner notes

No notes yet

Official description

Technical summary

Affected products & versions

CVSS breakdown

Am I affected?

Remediation

References