Auth bypass in Lexar F35

CVE-2021-46390

An access control issue in the authentication module of Lexar_F35 v1.0.34 allows attackers to access sensitive data and cause a Denial of Service (DoS). An attacker without access to securely protected data on a secure USB flash drive can bypass user authentication without having any information related to the password of the registered user. The secure USB flash drive transmits the password entered by the user to the authentication module in the drive after the user registers a password, and then the input password is compared with the registered password stored in the authentication module. Subsequently, the module returns the comparison result for the authentication decision. Therefore, an attacker can bypass password authentication by analyzing the functions that return the password verification or comparison results and manipulate the authentication result values. Accordingly, even if attackers enter an incorrect password, they can be authenticated as a legitimate user and can therefore exploit functions of the secure USB flash drive by manipulating the authentication result values.

Vulnerability class: Broken Authentication

EPSS: 0.005 (39.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2021-46390?
CVE-2021-46390 is a medium-severity vulnerability in Lexar F35, classified under Improper Authentication. CVSS score: 6.8/10. Published 2022-03-21.
How severe is CVE-2021-46390?
Medium severity. CVSS v3 base score is 6.8 out of 10.
Is CVE-2021-46390 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.