Is CVE-2021-20090 known to be exploited?

Yes. CVE-2021-20090 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03), indicating it is being actively exploited. 17 public proof-of-concept repositories are indexed.

Vulnerability in Buffalo Wsr-2533dhpl2, Wsr-2533dhp3

Q: What is CVE-2021-20090?

CVE-2021-20090 is a vulnerability in Buffalo Wsr-2533dhpl2, Wsr-2533dhp3. Published 2021-04-29.

CVE-2021-20090

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.

EPSS: 0.944 (100.0th percentile) — read the EPSS interpretation.

Affected products

N/a Buffalo Wsr-2533dhpl2, Wsr-2533dhp3 — versions WSR-2533DHPL2 <=1.02, WSR-2533DHP3 <= 1.24

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on 2021-11-03. CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.

BOD 22-01 due date: 2021-11-17.

Required action: Apply updates per vendor instructions.

Public proof-of-concept exploits

References

www.tenable.com/security/research/tra-2021-13
VU#914124 (third-party-advisory)
www.secpod.com/blog/arcadyan-based-routers-and-modems-under-active-exploitation/

Frequently asked questions

What is CVE-2021-20090?: CVE-2021-20090 is a vulnerability in Buffalo Wsr-2533dhpl2, Wsr-2533dhp3. Published 2021-04-29.
Is CVE-2021-20090 known to be exploited?: Yes. CVE-2021-20090 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03), indicating it is being actively exploited. 17 public proof-of-concept repositories are indexed.