CVE-2021-20090

CRITICAL KEV NUCLEI

Buffalo WSR-2533DHPL2 Firmware <= 1.02 and WSR-2533DHP3 Firmware <= 1.24 - Unauthenticated Path Traversal

Title source: llm

Exploitation Summary

CVE-2021-20090 is actively exploited and listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added November 3, 2021. A Nuclei detection template is also available.

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.

Nuclei Templates (1)

Buffalo WSR-2533DHPL2 - Path Traversal

CRITICALby gy741

References (4)

Core 4

Core References

Third Party Advisory, US Government Resource third-party-advisory

https://www.kb.cert.org/vuls/id/914124

Exploit, Third Party Advisory

https://www.secpod.com/blog/arcadyan-based-routers-and-modems-under-active-exploitation/

Exploit, Third Party Advisory

https://www.tenable.com/security/research/tra-2021-13

US Government Resource

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-20090

Scores

CVSS v3 9.8

EPSS 0.9440

EPSS Percentile 100.0%

Attack Vector NETWORK

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

CISA SSVC

Vulnrichment

Exploitation active

Automatable yes

Technical Impact total

Details

CISA KEV 2021-11-03

VulnCheck KEV 2021-08-06

InTheWild.io 2021-08-06

ENISA EUVD EUVD-2021-7547

CWE

CWE-22

Status published

Products (2)

buffalo/wsr-2533dhp3-bk_firmware < 1.24

buffalo/wsr-2533dhpl2-bk_firmware < 1.02

Published Apr 29, 2021

KEV Added Nov 03, 2021

Tracked Since Feb 18, 2026