CVE-2021-20090

criticalknown exploitedpublic exploitcovered by 1 sourcefirst seen 2021-11-03

Actively exploited. CVE-2021-20090 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03) — exploitation has been observed in the wild, and US federal agencies are required to remediate it under BOD 22-01. Treat patching as urgent.

Public exploit code is available. Proof-of-concept or working exploit code for CVE-2021-20090 is indexed in Nuclei. Expect opportunistic scanning and exploitation attempts — prioritize remediation.

Arcadyan Buffalo firmware contains a path traversal vulnerability that could allow unauthenticated, remote attackers to bypass authentication and access sensitive information. This vulnerability affects multiple routers across several different vendors.

CSIRTS triage

What: A path traversal vulnerability allows unauthenticated attackers to access sensitive information.
Who is affected: Users of routers with Arcadyan Buffalo firmware.
Urgency: Immediate action is required due to active exploitation and critical severity.
Action: Update the firmware of affected routers.

AI-assisted analysis generated from the source advisory — verify against the original.

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Exploitation outlook

Exploitation confirmedAlready exploited in the wild (CISA KEV) — the prediction phase is over. Patch now. Riskier than 100% of all EPSS-scored CVEs.

Exploit availability

Public exploit or proof-of-concept code for CVE-2021-20090 is indexed in these free datasets. Available exploit code raises real-world risk independent of the CVSS score.

NucleiA nuclei-templates detection/PoC template exists for this CVE.look it up ↗

Advisory coverage (1)

criticalexploitedCVE-2021-20090: Arcadyan Buffalo Firmware Path Traversal Vulnerabilitycisa-kev · 2021-11-03

External references

NVD record for CVE-2021-20090

CVE.org record

CISA KEV catalog

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