Microsoft WinVerifyTrust function Remote Code Execution

What to do

1. Check which version of Windows 10 Version 1809 you run against the affected versions below, and install the vendor's latest release.
2. CISA's required action: Apply updates per vendor instructions.
3. Read the advisory on msrc.microsoft.com for workarounds and exact fixed builds.
4. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
5. Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.

Affected products and versions

Version data comes from the organisation that assigned the CVE; 18 further products are omitted here. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector

NetworkCan be exploited remotely over a network, including the internet.

Attack complexity

LowNo special conditions are needed; the attack works reliably.

Privileges required

NoneNo account or login is needed.

User interaction

RequiredA user must take an action such as opening a file or link.

Scope

UnchangedImpact stays within the vulnerable component.

Confidentiality

HighAll data handled by the component can be read.

Integrity

HighData or code can be modified at will.

Availability

HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H. Scored by NVD.

Official 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

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Verification of Cryptographic Signature

Timeline

1. December 11, 2013CVE record published.
2. January 10, 2022Added to CISA's Known Exploited Vulnerabilities catalogue.
3. July 10, 2022Deadline for US federal agencies to remediate, set by CISA.
4. February 10, 2025CISA published its SSVC assessment (exploitation: active, automatable: no, technical impact: partial).
5. October 7, 2026Record last changed materially (score, affected products, status or references).

References

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