CVE-2021-1492: Duo Authentication Proxy

High severity, CVSS 7.1. EPSS: 0.3% chance of exploitation in the next 30 days.

The Duo Authentication Proxy installer prior to 5.2.1 did not properly validate file installation paths. This allows an attacker with local user privileges to coerce the installer to write to arbitrary privileged directories. If successful, an attacker can manipulate files used by Duo Authentication Proxy installer, cause Denial of Service (DoS) by deleting file(s), or replace system files to potentially achieve elevation of privileges. This is only exploitable during new installations, while the installer is running, and is not exploitable once installation has finished. Versions 5.2.1 of Duo Authentication Proxy installer addresses this issue.

Affected products

• Duo Authentication Proxy: before 5.2.1 (fixed in 5.2.1)

Published 2021-03-25. Last modified 2026-06-17.