How severe is CVE-2021-20680?

CVE-2021-20680 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2021-20680 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-20680?

CVE-2021-20680 primarily affects Nec Aterm Wg1900hp2 Firmware. In total, 17 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-20680?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-20680 published?

CVE-2021-20680 was published on 2021-04-26 and last updated on 2026-06-17.

CVE-2021-20680

CVE-2021-20680 is a medium-severity vulnerability in Nec Aterm Wg1900hp2 Firmware with a CVSS 3.x base score of 6.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Severity: Medium (CVSS 3.x base score 6.1)
CVSS v2: 4.3
EPSS exploit prediction: 1% (52nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Nec Aterm Wg1900hp2 Firmware
Published: 2021-04-26
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2021-20680?: 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.
How severe is CVE-2021-20680?: CVE-2021-20680 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2021-20680 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-20680?: CVE-2021-20680 primarily affects Nec Aterm Wg1900hp2 Firmware. In total, 17 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-20680?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-20680 published?: CVE-2021-20680 was published on 2021-04-26 and last updated on 2026-06-17.

References

Affected products (17)

cpe:2.3:o:nec:aterm_wg1900hp2_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:nec:aterm_wg1900hp_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:nec:aterm_wg1800hp4_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:nec:aterm_wg1800hp3_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:nec:aterm_wg1200hs3_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:nec:aterm_wg1200hs2_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:nec:aterm_wg1200hp3_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:nec:aterm_wg1200hp2_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:nec:aterm_w1200ex_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:nec:aterm_w1200ex-ms_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:nec:aterm_wg1200hs_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:nec:aterm_wg1200hp_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:nec:aterm_wf800hp_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:nec:aterm_wf300hp2_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:nec:aterm_wr8165n_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:nec:aterm_w500p_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:nec:aterm_w300p_firmware:*:*:*:*:*:*:*:*

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