CVE-2020-1020VulnerabilityPublished 11/03/2021Updated 10/24/2026

CVE-2020-1020: Microsoft Windows Adobe Font Manager Library Remote Code Execution Vulnerability

Affects Microsoft WindowsSource CISA KEV

Severity

High

No CVSS score published yet

Exploitation: Actively exploited – in CISA KEV since 11/03/2021
KEV deadline: 05/03/2022
EPSS: 65.0% chance of exploitation in 30 days – higher than 99% of CVEs

What to do

CISA required action

Apply updates per vendor instructions.

nvd.nist.gov/vuln/detail/CVE-2020-1020 (opens in a new tab)

Description

CVE-2020-1020 is a remote code execution vulnerability in the Microsoft Windows Adobe Font Manager Library related to handling specially crafted multi-master fonts in Adobe Type 1 PostScript format. It affects all Windows systems except Windows 10. On Windows 10, exploitation results in code execution within a restricted AppContainer sandbox with limited privileges. The vulnerability has been exploited in the wild.

Summary

The Microsoft Windows Adobe Font Manager Library contains an unspecified vulnerability when processing specially crafted multi-master fonts (Adobe Type 1 PostScript format). This flaw allows remote attackers to execute arbitrary code on affected systems. Systems running Windows versions other than Windows 10 are fully vulnerable to remote code execution. On Windows 10, successful exploitation results in code execution confined to an AppContainer sandbox, limiting the attacker's capabilities. The vulnerability is tracked as CVE-2020-1020 and has been observed in active exploitation campaigns.

Impact

Successful exploitation allows remote code execution on affected Windows systems. Non-Windows 10 systems are fully compromised, enabling attackers to run arbitrary code with system privileges. On Windows 10, the attacker gains code execution only within a sandboxed AppContainer environment, restricting the potential impact. This vulnerability has been exploited in the wild, indicating active threat usage.

Mitigation

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No specific patch or official fix information is provided in the available data. Users should monitor Microsoft advisories for updates addressing this vulnerability.

Weaknesses

CWE-787Out-of-bounds Write (opens in a new tab)

What to do

Description

AnalysisAI-generated, updated 10/24/2026, 09:19:29 UTC

Weaknesses

References

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