CVE-2021-20680

What it is

Cross-site scripting vulnerability in NEC Aterm devices (Aterm WG1900HP2 firmware Ver.1.3.1 and earlier, Aterm WG1900HP firmware Ver.2.5.1 and earlier, Aterm WG1800HP4 firmware Ver.1.3.1 and earlier, Aterm WG1800HP3 firmware Ver.1.5.1 and earlier, Aterm WG1200HS2 firmware Ver.2.5.0 and earlier, Aterm WG1200HP3 firmware Ver.1.3.1 and earlier, Aterm WG1200HP2 firmware Ver.2.5.0 and earlier, Aterm W1200EX firmware Ver.1.3.1 and earlier, Aterm W1200EX-MS firmware Ver.1.3.1 and earlier, Aterm WG1200HS firmware all versions Aterm WG1200HP firmware all versions Aterm WF800HP firmware all versions Aterm WF300HP2 firmware all versions Aterm WR8165N firmware all versions Aterm W500P firmware all versions, and Aterm W300P firmware all versions) allows remote attackers to inject arbitrary script or HTML via unspecified vectors.

At a glance

Exploitability

Can be exploited over the network without logging in, but needs a user to act. Limited direct impact.

Exploit odds

0.8% 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: 0.8% in the next 30 days (EPSS).
• Severity: 6.1 MEDIUM (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

0.8% · EPSS, next 30 days

Weakness

CWE-79 · Cross-site scripting

Record status

Modified

Affected

• Nec Aterm wg1900hp2 Firmware ≤ 1.3.1
• Nec Aterm wg1900hp Firmware ≤ 2.5.1
• Nec Aterm wg1800hp4 Firmware ≤ 1.3.1
• Nec Aterm wg1800hp3 Firmware ≤ 1.5.1
• Nec Aterm wg1200hs3 Firmware ≤ 1.1.2
• Nec Aterm wg1200hs2 Firmware ≤ 2.5.0
• Nec Aterm wg1200hp3 Firmware ≤ 1.3.1
• Nec Aterm wg1200hp2 Firmware ≤ 2.5.0

Attack profile CVSS 3.1 · 6.1

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

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-2021-20680.md and follow it. Check whether this project is affected by CVE-2021-20680. 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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