CVE-2025-13943
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 · uneditedA post-authentication command injection vulnerability in the log file download function of the Zyxel EX3301-T0 firmware versions through 5.50(ABVY.7)C0 could allow an authenticated attacker to execute operating system (OS) commands on an affected device.
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 confidenceA post-authentication command injection vulnerability exists in the log file download function of Zyxel EX3301-T0 firmware versions through 5.50(ABVY.7)C0. An authenticated attacker can inject and execute arbitrary operating system commands by providing specially crafted input to the log download functionality, likely through unsanitized parameters that get passed to a system shell.
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< 5.70\(acdz.5.1\)c0< 5.18\(achn.3.1\)c0< 5.18\(acak.1.6\)c0< 5.18\(accl.2\)c0< 5.61\(ackk.1.2\)c0< 5.50\(abpm.9.7\)c0< 5.17\(abqa.3.2\)c0< 5.17\(abqa.3.2\)c0CVSS 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
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/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 checksWork through these to decide whether this CVE applies to you.
-
Identify device model and firmware versionAccess the router web admin interface or check the device label, then navigate to Status or System Info page to find the exact firmware version string (e.g., 5.50(ABVY.7)C0)Affected if The device model matches one in the affected list and the firmware version is below the specified threshold for that model
-
Compare firmware version against affected rangesMatch your firmware version to the affected list: Ex5601 T1 < 5.70(acdz.5.1)c0, Ex7501 B0 < 5.18(achn.3.1)c0, Ex7710 B0 < 5.18(acak.1.6)c0, Gm4100 B0 < 5.18(accl.2)c0, Pm7500 00 < 5.61(ackk.1.2)c0, Vmg3625 T50b < 5.50(abpm.9.7)c0, Vmg4005 B50a/B60a < 5.17(abqa.3.2)c0Affected if Your installed version is lower than the version threshold listed for your specific model
-
Check if administrative interface is remotely accessibleVerify router firewall settings or port forward rules to determine if the web admin interface (port 80/443) is exposed to the internet or untrusted networksAffected if The admin interface is accessible from WAN/untrusted networks, allowing external attackers to potentially authenticate and exploit the vulnerability
-
Verify log download function is accessibleLog into the admin interface and navigate to Maintenance, Logs, or System Log section to confirm the log file download feature exists and is accessibleAffected if The log download feature is present and accessible to authenticated users
You are affected if your Zyxel device model matches one in the affected list AND your firmware version is below the specified threshold AND the admin interface is accessible to untrusted users.
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 · scoped5.175.185.50
Apply vendor firmware patch when available; if no patch exists, disable or restrict the log download feature to trusted administrators only and implement strict input validation on any user-supplied parameters in the affected function.
Upgrade to firmware version >=5.70(acdz.5.1)c0 for Ex5601 T1, >=5.18(achn.3.1)c0 for Ex7501 B0, >=5.18(acak.1.6)c0 for Ex7710 B0, >=5.18(accl.2)c0 for Gm4100 B0, >=5.61(ackk.1.2)c0 for Pm7500 00, >=5.50(abpm.9.7)c0 for Vmg3625 T50b, or >=5.17(abqa.3.2)c0 for Vmg4005 B50a/B60a (or latest available fr
- 1. Identify the specific Zyxel device model from the affected products list (Ex5601 T1, Ex7501 B0, Ex7710 B0, Gm4100 B0, Pm7500 00, Vmg3625 T50b, Vmg4005 B50a, or Vmg4005 B60a)
- 2. Determine the current firmware version installed on the device via the web management interface or CLI
- 3. Navigate to Zyxel support website (www.zyxel.com) and locate the firmware download section for your specific device model
- 4. Download the latest stable firmware version that meets or exceeds the fixed version threshold for your device: Ex5601 T1 requires >=5.70(acdz.5.1)c0, Ex7501 B0 requires >=5.18(achn.3.1)c0, Ex7710 B0 requires >=5.18(acak.1.6)c0, Gm4100 B0 requires >=5.18(accl.2)c0, Pm7500 00 requires >=5.61(ackk.1.2)c0, Vmg3625 T50b requires >=5.50(abpm.9.7)c0, Vmg4005 B50a/B60a requires >=5.17(abqa.3.2)c0
- 5. Back up the current device configuration
- 6. Upload and install the new firmware via the web management interface or CLI following Zyxel's standard upgrade procedure
- 7. After upgrade, verify the firmware version and confirm the device is functioning normally
- 8. Test that the log file download function works correctly without command injection vulnerability
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation6.0 h
- Implementation4.0 h
- Testing8.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,144.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-13943 — 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-2025-13943 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
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.
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.
- 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