CVE-2021-20864

moderate-risk

Published 2021-12-01

Improper access control vulnerability in ELECOM routers (WRC-1167GST2 firmware v1.25 and prior, WRC-1167GST2A firmware v1.25 and prior, WRC-1167GST2H firmware v1.25 and prior, WRC-2533GS2-B firmware v1.52 and prior, WRC-2533GS2-W firmware v1.52 and prior, WRC-1750GS firmware v1.03 and prior, WRC-1750GSV firmware v2.11 and prior, WRC-1900GST firmware v1.03 and prior, WRC-2533GST firmware v1.03 and prior, WRC-2533GSTA firmware v1.03 and prior, WRC-2533GST2 firmware v1.25 and prior, WRC-2533GST2SP firmware v1.25 and prior, WRC-2533GST2-G firmware v1.25 and prior, and EDWRC-2533GST2 firmware v1.25 and prior) allows a network-adjacent unauthenticated attacker to bypass access restriction, and to start the telnet service and execute an arbitrary OS command via unspecified vectors.

Do I need to act?

0.24% chance of exploitation

EPSS score — low exploit probability

Not on CISA KEV list

No confirmed active exploitation reported to CISA

Patch status unknown

Check vendor advisories for fix availability and mitigation guidance

CVSS 8.8/10 High

ADJACENT_NETWORK / LOW complexity

Affected Products (14)

Wrc-1167Gst2 Firmware

Wrc-1167Gst2A Firmware

Wrc-1167Gst2H Firmware

Wrc-2533Gs2-B Firmware

Wrc-2533Gs2-W Firmware

Wrc-1750Gs Firmware

Wrc-1750Gsv Firmware

Wrc-1900Gst Firmware

Wrc-2533Gst Firmware

Wrc-2533Gst2 Firmware

Wrc-2533Gsta Firmware

Wrc-2533Gst2Sp Firmware

Wrc-2533Gst2-G Firmware

Edwrc-2533Gst2 Firmware

Affected Vendors

Elecom

References (4)

Third Party Advisory https://jvn.jp/en/vu/JVNVU94527926/index.html

Vendor Advisory https://www.elecom.co.jp/news/security/20211130-01/

Third Party Advisory https://jvn.jp/en/vu/JVNVU94527926/index.html

Vendor Advisory https://www.elecom.co.jp/news/security/20211130-01/

/ 100

moderate-risk

Severity 27/34 · High

Exploitability 1/34 · Minimal

Exposure 18/34 · Moderate