CVE-2020-1421: Microsoft Windows LNK file type confusion remote code execution

Automated analysis

Generated by VULONE's analysis model from the NVD record, CISA KEV and EPSS data on 18 September 2026. Confidence: medium.

high priorityCVSS 8.8 with a very high EPSS percentile and required user interaction make this a serious, likely-targeted flaw despite no KEV listing.

What it is

CVE-2020-1421 is a type confusion flaw (CWE-843) in Microsoft Windows that can lead to remote code execution when a .LNK file is processed. It matters because shortcut files are commonly exchanged and opened, and successful exploitation runs code with the rights of the logged-on user.

Impact

An attacker who exploits the flaw gains code execution at the privilege level of the local user, which can mean full control of data and settings available to that account. The CVSS vector rates confidentiality, integrity and availability impact as high.

Attack surface

The vector is network-reachable with no privileges required, but user interaction is required: the victim must process a malicious .LNK file. No authentication is needed on the attacker's side.

Exploitation

The record shows no CISA KEV listing and no ransomware association, but EPSS is very high at 0.745 (99.47th percentile), indicating strong predicted exploitation activity. Reference tags are limited to patch and advisory entries, so no confirmed in-the-wild exploitation is documented here.

What to do

• Apply the Microsoft security update for CVE-2020-1421 as the first action.
• Block or restrict execution and delivery of .LNK files from email, web downloads and removable media.
• Disable or harden Windows shortcut handling where business needs allow, and enforce attachment filtering at the mail gateway.
• Run users with least privilege so exploitation yields limited rights.
• Monitor vendor advisories for updated guidance on affected Windows builds.

Detection

• Alert on .LNK files written to or executed from temp, download or email attachment directories.
• Monitor process creation where explorer.exe or similar parents spawn unusual child processes from shortcut launches.
• Hunt for .LNK files arriving via email or browser download with suspicious target paths or command-line arguments.
• Correlate endpoint telemetry for shortcut execution followed by script interpreter or LOLBin activity.

This assessment is produced automatically and is not human-reviewed. Verify against the vendor advisory before acting on it.