Arbitrary file upload in Asus Dsl-N14u B1

CVE-2021-3166

An issue was discovered on ASUS DSL-N14U-B1 1.1.2.3_805 devices. An attacker can upload arbitrary file content as a firmware update when the filename Settings_DSL-N14U-B1.trx is used. Once this file is loaded, shutdown measures on a wide range of services are triggered as if it were a real update, resulting in a persistent outage of those services.

Vulnerability class: Unrestricted File Upload

EPSS: 0.029 (85.4th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2021-3166?
CVE-2021-3166 is a high-severity vulnerability in Asus Dsl-N14u B1, classified under Unrestricted Upload of File with Dangerous Type. CVSS score: 7.5/10. Published 2021-01-18.
How severe is CVE-2021-3166?
High severity. CVSS v3 base score is 7.5 out of 10.
Is CVE-2021-3166 known to be exploited?
6 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.