What’s Vulnerable › Vulnerabilities

CVE-2020-16921: Windows Text Services Framework Information Disclosure Vulnerability

• Severity: low (CVSS 2.1 v2.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2020-10-16 · updated 2026-06-17

Description

<p>An information disclosure vulnerability exists in Text Services Framework when it fails to properly handle objects in memory. An attacker who successfully exploited this vulnerability could potentially read data that was not intended to be disclosed. Note that this vulnerability would not allow an attacker to execute code or to elevate their user rights directly, but it could be used to obtain information that could be used to try to further compromise the affected system.</p> <p>To exploit this vulnerability, an attacker would have to log on to an affected system and open a specially crafted file.</p> <p>The update addresses the vulnerability by correcting how Text Services Framework handles objects in memory.</p>

Affected products

• Microsoft Windows 10 Version 1607: 1709, 1803, 1809, 1903, 1909, 2004
• Microsoft Windows Server 2016: 1903, 1909, 2004
• Microsoft Windows Server 2019: all versions
• Microsoft Windows 10 1709: from 10.0.0 before publication — fixed in publication
• Microsoft Windows 10 Version 1709 for 32-bit Systems: from 10.0.0 before publication — fixed in publication
• Microsoft Windows 10 1803: from 10.0.0 before publication — fixed in publication
• Microsoft Windows 10: from 10.0.0 before publication — fixed in publication
• Microsoft Windows 10 Version 1903 for 32-bit Systems: from 10.0.0 before publication — fixed in publication
• Microsoft Windows 10 Version 1903 for ARM64-based Systems: from 10.0.0 before publication — fixed in publication
• Microsoft Windows 10 Version 1903 for x64-based Systems: from 10.0.0 before publication — fixed in publication
• Microsoft Windows 10 1909: from 10.0.0 before publication — fixed in publication
• Microsoft Windows 10 2004: from 10.0.0 before publication — fixed in publication
• Microsoft Windows Server 2019: from 10.0.0 before publication — fixed in publication
• Microsoft Windows Server, version 1903 (Server Core installation): from 10.0.0 before publication — fixed in publication
• Microsoft Windows Server, version 1909 (Server Core installation): from 10.0.0 before publication — fixed in publication
• Microsoft Windows Server version 2004: from 10.0.0 before publication — fixed in publication

How to fix

Upgrade to a fixed version: Microsoft Windows 10 1709 publication; Microsoft Windows 10 Version 1709 for 32-bit Systems publication; Microsoft Windows 10 1803 publication; Microsoft Windows 10 publication; Microsoft Windows 10 Version 1903 for 32-bit Systems publication; Microsoft Windows 10 Version 1903 for ARM64-based Systems publication; Microsoft Windows 10 Version 1903 for x64-based Systems publication; Microsoft Windows 10 1909 publication; Microsoft Windows 10 2004 publication; Microsoft Windows Server 2019 publication; Microsoft Windows Server, version 1903 (Server Core installation) publication; Microsoft Windows Server, version 1909 (Server Core installation) publication. Check the vendor advisory for mitigations.

References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-16921
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-16921

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