CVE-2021-20621: Cross-site request forgery (CSRF) vulnerability in Aterm WG2600HP firmware Ver1.0.2 and earlier, and Aterm WG2

Q: How do I fix CVE-2021-20621?

wg2600hp firmware: upgrade to newer than 1.0.2; wg2600hp2 firmware: upgrade to newer than 1.0.2. Exact commands for each OS are on this page.

Q: Is CVE-2021-20621 being exploited?

CVE-2021-20621 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2021-20621 affect?

CVE-2021-20621 affects wg2600hp firmware, wg2600hp2 firmware. Severity is high (CVSS 8.8). Cross-site request forgery (CSRF) vulnerability in Aterm WG2600HP firmware Ver1.0.2 and earlier, and Aterm WG2600HP2 firmware Ver1.0.2 and earlier allows remote attackers to hijack the authentication of administrators via unspecified vector

This month

HIGH 8.8UPGRADEUPGRADE

CVE-2021-20621 is a high-severity flaw (CVSS 8.8) affecting wg2600hp firmware, wg2600hp2 firmware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Cross-site request forgery (CSRF) vulnerability in Aterm WG2600HP firmware Ver1.0.2 and earlier, and Aterm WG2600HP2 firmware Ver1.0.2 and earlier allows remote attackers to hijack the authentication of administrators via unspecified vectors.

Why this priority

High severity

A fixed release or distro patch exists.

Risk facts

CVSS score	8.8 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.7% (top 49%)
CISA exploited list	No
Weakness	CWE-352
Published	2021-01-28
Last modified	2026-06-17

Publisher (CNA): JPCERT/CC · Vendor: aterm

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2021-01-28 11:15 UTCPublished CVE record published
2026-06-17 03:34 UTCUpdated Record last modified

aterm wg2600hp firmware UPGRADE

Affected: <= 1.0.2

Fixed in: newer than 1.0.2

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

aterm wg2600hp2 firmware UPGRADE

Affected: <= 1.0.2

Fixed in: newer than 1.0.2

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2021-20621?

wg2600hp firmware: upgrade to newer than 1.0.2; wg2600hp2 firmware: upgrade to newer than 1.0.2. Exact commands for each OS are on this page.

Is CVE-2021-20621 being exploited?

CVE-2021-20621 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2021-20621 affect?

CVE-2021-20621 affects wg2600hp firmware, wg2600hp2 firmware. Severity is high (CVSS 8.8). Cross-site request forgery (CSRF) vulnerability in Aterm WG2600HP firmware Ver1.0.2 and earlier, and Aterm WG2600HP2 firmware Ver1.0.2 and earlier allows remote attackers to hijack the authentication of administrators via unspecified vector

How urgent is CVE-2021-20621?

Priority 44/100. High severity

Related CVEs

CVE-2021-20622 MEDIUM 6.1 UPGRADE UPGRADE Cross-site scripting vulnerability in Aterm WG2600HP firmware Ver1.0.2 and earlier, and Aterm WG2600HP2 firmwa
CVE-2021-20620 MEDIUM 6.1 UPGRADE Cross-site scripting vulnerability in Aterm WF800HP firmware Ver1.0.9 and earlier allows remote attackers to i

References

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