CVE-2021-1492
Duo Authentication Proxy Installer Denial of Service Vulnerability
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.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- Required
What an attacker can affect
- Confidentiality
- None
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Duo Authentication Proxy Installer Denial of Service Vulnerability
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.
- Record
CVE-2021-1492- CVSS 3.1
- 6.6 Medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:H/A:H - Weakness
- CWE-64
- Updated
- 2026-11-02
EUVDEUVD-2021-6959
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.
- Record
EUVD-2021-6959- CVSS 3.1
- 6.6 Medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:H/A:H - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-5hf3-34gj-8w5g No score
The Duo Authentication Proxy installer prior to 5.2.1 did not properly validate file installation...
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.
- Record
GHSA-5hf3-34gj-8w5g- Weakness
- CWE-64
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2021-1492- CVSS 3.1
- 6.6 Medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:H/A:H - CVSS 3.1
- 7.1 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H - CVSS 2.0
- 3.6 Low
AV:L/AC:L/Au:N/C:N/I:P/A:P - Weakness
- CWE-64
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-1492 is a medium vulnerability (CVSS 6.6) in Cisco Duo Authentication Proxy, published March 25, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.28%, the 20th percentile. No source names a fixed version.