Security News > 2023 > March > 10-year-old Windows bug with 'opt-in' fix exploited in 3CX attack
A 10-year-old Windows vulnerability is still being exploited in attacks to make it appear that executables are legitimately signed, with the fix from Microsoft still "Opt-in" after all these years.
Even worse, the fix is removed after upgrading to Windows 11.
On Wednesday night, news broke that VoIP communications company 3CX was compromised to distribute trojanized versions of its Windows desktop application in a large-scale supply chain attack.
When a signed executable is modified, Windows will display a message stating that the "Digital signature of the object did not verify." However, even though we know that the d3dcompiler 47.dll DLL was modified, it still showed as signed in Windows.
"On December 10, 2013, Microsoft released an update for all supported releases of Microsoft Windows that changes how signatures are verified for binaries signed with the Windows Authenticode signature format," explains Microsoft's disclosure for the CVE-2013-3900.
"When enabled, the new behavior for Windows Authenticode signature verification will no longer allow extraneous information in the WIN CERTIFICATE structure, and Windows will no longer recognize non-compliant binaries as signed."
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Related Vulnerability
| DATE | CVE | VULNERABILITY TITLE | RISK |
|---|---|---|---|
| 2013-12-11 | CVE-2013-3900 | Improper Verification of Cryptographic Signature vulnerability in Microsoft products 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. | 8.8 |