CVE-2020-3427

Duo Authentication for Windows Logon and RDP Privilege Escalation Vulnerability

HIGH
7.8
CVSS Score
Published: October 14, 2020 at 06:15 PM UTC
Updated: June 17, 2026 at 03:18 AM UTC
1 product affected across 1 vendorDuo Authentication for Windows Logon and RDP

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Severity
HIGH7.8
Exploit prediction
EPSS 0.3%
SSVC
No known exploit

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 4.1.2
Affected range stops below 4.1.2, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

References (1)

Vendor Advisoryx_refsource_CISCORelease Notes
https://duo.com/docs/rdp-notes

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-280NVD-CWE-noinfo

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