How severe is CVE-2021-20090?

CVE-2021-20090 has a CVSS 3.1 base score of 9.8 (CRITICAL). EPSS estimates a 100.0% probability of exploitation in the next 30 days. It is listed in the CISA Known Exploited Vulnerabilities catalog.

CVE-2021-20090: Arcadyan Buffalo Firmware Path Traversal

CISA Known Exploited Vulnerabilities

Arcadyan Buffalo Firmware Path Traversal Vulnerability is confirmed as actively exploited and is listed in the CISA KEV catalog.

Added to KEV

2021-11-03

Remediation due

2021-11-17

Required action
Apply updates per vendor instructions.

CISA notes
https://nvd.nist.gov/vuln/detail/CVE-2021-20090

Description

A path traversal vulnerability in the web interfaces of Buffalo WSR-2533DHPL2 firmware version <= 1.02 and WSR-2533DHP3 firmware version <= 1.24 could allow unauthenticated remote attackers to bypass authentication.

Severity

CVSS 3.1 · CISA9.8 CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

SSVC · CISA-ADP

Exploitationactive

Automatableyes

Technical impacttotal

Affected Products

Vendor	Product	Affected versions
-	Buffalo WSR-2533DHPL2, Buffalo WSR-2533DHP3	WSR-2533DHPL2 <=1.02, WSR-2533DHP3 <= 1.24

References

3 Links

Third-party advisories

VU#914124

Other references

Record Details

Published

2021-04-29

Last updated

2025-10-21

Assigner (CNA)

tenable

Credited to

CVE record data © The MITRE Corporation, used under the CVE Terms of Use. Exploited-in-the-wild data from the CISA Known Exploited Vulnerabilities catalog (CC0). Exploit prediction scores by FIRST EPSS (first.org/epss). This site is not endorsed or certified by MITRE, NVD, CISA, or FIRST.