What’s Vulnerable › Vulnerabilities

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

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: yes — in CISA KEV since 2021-11-03
• EPSS: 100.0% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2021-04-29 · updated 2026-06-17
• Weakness: CWE-22

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.

Affected products

• Buffalo Wsr-2533Dhp3-Bk Firmware: through 1.24
• Buffalo Wsr-2533Dhpl2-Bk Firmware: through 1.02

References

• https://www.kb.cert.org/vuls/id/914124
• https://www.secpod.com/blog/arcadyan-based-routers-and-modems-under-active-exploitation/
• https://www.tenable.com/security/research/tra-2021-13
• https://www.kb.cert.org/vuls/id/914124
• https://www.secpod.com/blog/arcadyan-based-routers-and-modems-under-active-exploitation/
• https://www.tenable.com/security/research/tra-2021-13
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-20090

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