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TI-2020-02976 Aliases CVE-2020-3427GHSA-437m-6wfg-j372

Duo Authentication for Windows Logon and RDP Privilege Escalation Vulnerability

Priority LOW 36CWE-280Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA.

Summary

The Windows Logon installer prior to 4.1.2 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 Windows Logon, cause Denial of Service (DoS) by deleting file(s), or replace system files to potentially achieve elevation of privileges. Note that this can only exploitable during new installations while the installer is running and is not exploitable once installation is finished. Versions 4.1.2 of Windows Logon addresses this issue.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00306 23rd percentileScored 2026-11-07
Fix Fixed Duo Authentication for Windows Logon and RDP (Cisco): 4.1.2

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
CiscoDuo Authentication for Windows Logon and RDPbefore 4.1.24.1.2Patch availableCNA
  • Duo Authentication for Windows Logon and RDP VendorCisco Affected before 4.1.2 Fixed in 4.1.2 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:cisco:duo_authentication_for_windows_logon_and_rdp:*:*:*:*:*:*:*:*before 4.1.2VulnerableCisco
  • cpe:2.3:a:cisco:duo_authentication_for_windows_logon_and_rdp:*:*:*:*:*:*:*:* Versions before 4.1.2 Vulnerable ·Cisco

Remediation

  • Fix · CNA Duo Authentication for Windows Logon and RDP (Cisco) Fixed in 4.1.2

Timeline

  1. 2026-10-02 Threatist record created from CVE-2020-3427
  2. 2026-10-03 Alias added: GHSA-437m-6wfg-j372

References

Advisory 1

  • TI-2023-06830 Cisco Duo Authentication for macOS and Duo Authentication for Windows Logon Offline Credentials Replay Vulnerability CVSS 3.1MEDIUM 6.3
  • TI-2024-13235 Improper authentication in Cisco Duo CVSS 3.1MEDIUM 6.2
  • TI-2024-13226 Information disclosure in Cisco Duo CVSS 3.1MEDIUM 5.5

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences