CVE-2021-20709

What it is

Improper validation of integrity check value vulnerability in NEC Aterm WF1200CR firmware Ver1.3.2 and earlier, Aterm WG1200CR firmware Ver1.3.3 and earlier, and Aterm WG2600HS firmware Ver1.5.1 and earlier allows an attacker with an administrative privilege to execute arbitrary OS commands by sending a specially crafted request to a specific URL.

At a glance

Exploitability

Can be exploited over the network with an admin-level account. High risk of data exposure, data tampering, service disruption.

Exploit odds

0.7% chance of exploitation in the next 30 days (EPSS).

Fix

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

Timeline

1. 2021-04-26 01:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 03:34 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.7% in the next 30 days (EPSS).
• Severity: 7.2 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2021-04-26 01:15 UTC

Last modified

2026-06-17 03:34 UTC

Exploit probability

0.7% · EPSS, next 30 days

Weakness

CWE-354

Record status

Modified

Affected

• Nec Aterm wf1200cr Firmware ≤ 1.3.2
• Nec Aterm wg1200cr Firmware ≤ 1.3.3
• Nec Aterm wg2600hs Firmware ≤ 1.5.1

Attack profile CVSS 3.1 · 7.2

Attack vector

Network

Complexity

Low

Privileges needed

High

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

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-2021-20709.md and follow it. Check whether this project is affected by CVE-2021-20709. 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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