Is CVE-2021-20090 exploited in the wild?

Yes. CVE-2021-20090 is known to be exploited in the wild, first recorded on 3 November 2021. Treat it as urgent.

How severe is CVE-2021-20090?

Critical severity, with a CVSS score of 9.8, published 3 November 2021.

Which products and versions are affected?

Buffalo WSR-2533DHPL2 firmware <= 1.02; Buffalo WSR-2533DHP3 firmware <= 1.24.

Is there a fix for CVE-2021-20090?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

How is CVE-2021-20090 attacked?

It is attacked over the network, in device firmware.

Am I affected by CVE-2021-20090?

Check whether you run Arcadyan Buffalo Firmware. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2021-20090: Arcadyan Buffalo Firmware Path Traversal Vulnerability

Q: Is there a fix for CVE-2021-20090?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

Q: How is CVE-2021-20090 attacked?

It is attacked over the network, in device firmware.

Q: Am I affected by CVE-2021-20090?

Check whether you run Arcadyan Buffalo Firmware. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2021-20090 · Severity: critical · CVSS 9.8 · Exploited in the wild · Published 2021-11-03

A path traversal vulnerability in the web interfaces of certain Buffalo router firmware allows unauthenticated remote attackers to bypass authentication. This flaw can be leveraged to access sensitive information and has been observed in active exploitation.

Quick answers

Is CVE-2021-20090 exploited in the wild?: Yes. CVE-2021-20090 is known to be exploited in the wild, first recorded on 3 November 2021. Treat it as urgent.
How severe is CVE-2021-20090?: Critical severity, with a CVSS score of 9.8, published 3 November 2021.
Which products and versions are affected?: Buffalo WSR-2533DHPL2 firmware <= 1.02; Buffalo WSR-2533DHP3 firmware <= 1.24.
Is there a fix for CVE-2021-20090?: No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2021-20090 attacked?: It is attacked over the network, in device firmware.
Am I affected by CVE-2021-20090?: Check whether you run Arcadyan Buffalo Firmware. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Affected products

Buffalo WSR-2533DHPL2 firmware <= 1.02
Buffalo WSR-2533DHP3 firmware <= 1.24

Timeline

2021-04-29: disclosed: NVD Published Date
2021-11-03: kev added: Date added to CISA Known Exploited Vulnerabilities Catalog
2021-11-03: advisory: Publication date of the provided advisory
2021-11-03: exploited: Reported as exploited in the wild in the advisory and CISA KEV catalog

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