CVE-2021-20090Arcadyan Buffalo Firmware Path Traversal Vulnerability

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.

9.8 CRITICALEPSS 99.98%⚡ Known Exploited (CISA KEV)NVD: Analyzed

Last updated: 2026-06-17 03:33 UTC

OverviewCVSS details

9.8CRITICALCVSS 3.1

Score source: NVD
NVD status: Analyzed
Published: Apr 29, 2021
Assigner: tenable

Affected

Buffalo WSR-2533DHPL2, Buffalo WSR-2533DHP3

Versions: WSR-2533DHPL2 <=1.02, WSR-2533DHP3 <= 1.24

Exploitation

Public exploit: Yes · 2 references
CISA KEV: Listed · Nov 3, 2021
KEV due date: Nov 17, 2021
Ransomware use: Unknown
SSVC: Exploitation active · Automatable yes · Impact total

EPSS · FIRST, scored Nov 7

99.98%chance of exploitation in 30 days

Higher than 99.98% of CVEs

CVSS 3.1 · NVD

9.8Critical

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

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: High

CVSS 2.0 · NVD

7.5High

AV:N/AC:L/Au:N/C:P/I:P/A:P

Attack vector: Network
Attack complexity: Low
Authentication: None
Confidentiality impact: Partial
Integrity impact: Partial
Availability impact: Partial

NVD status: Analyzed

Overview Affected Products References

NVD CVE.org

Overview

Severity

Score	Severity	Version	Vector String
9.8	CRITICAL	3.1NVD	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.5	HIGH	2.0NVD	AV:N/AC:L/Au:N/C:P/I:P/A:P

CISA required action

⚡ Known exploited · remediation due Nov 17, 2021

Apply updates per vendor instructions.

Details

CVE ID: CVE-2021-20090
Status: Analyzed
Assigner (CNA): tenable
Published: Apr 29, 2021
Last modified: 2026-06-17 03:33 UTC
Weaknesses: CWE-22

Sources

Refreshed hourly from the sources above. Last fetched 2026-11-08 09:49 UTC.