CVE-2020-28899

What it is

The Web CGI Script on ZyXEL LTE4506-M606 V1.00(ABDO.2)C0 devices does not require authentication, which allows remote unauthenticated attackers (via crafted JSON action data to /cgi-bin/gui.cgi) to use all features provided by the router. Examples: change the router password, retrieve the Wi-Fi passphrase, send an SMS message, or modify the IP forwarding to access the internal network.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data exposure, data tampering.

Exploit odds

1.7% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2021-03-16 17:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 03:10 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 1.7% in the next 30 days (EPSS).
• Severity: 9.1 CRITICAL (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2021-03-16 17:15 UTC

Last modified

2026-06-17 03:10 UTC

Exploit probability

1.7% · EPSS, next 30 days

Weakness

CWE-306 · Missing authentication

Record status

Modified

Affected

• Zyxel lte4506-m606 Firmware < v1.00\(abdo.6\)c0
• Zyxel lte7460-m608 Firmware < v1.00\(abfr.5\)c0
• Zyxel wah7706 Firmware < v1.00\(abbc.11\)c0

Attack profile CVSS 3.1 · 9.1

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2020-28899.md and follow it. Check whether this project is affected by CVE-2020-28899. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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