Windows Users Getting Bitten by Macrovision Zero Day
Microsoft and Macrovision are working to neutralize a zero-day flaw that could cause a complete system takeover. — Microsoft is working with Macrovision to check out a flaw in a driver on Windows Server 2003 and Windows XP that's …
Context & Ripple Effects
This is at least the third time in two years that a zero-day has landed on Windows through code Microsoft did not write. The Windows Metafile flaw of December 2005 was judged severe enough to force an out-of-cycle patch, and a QuickTime zero-day opened 2007 by hitting Macs and PCs alike. Now the hole sits in secdrv.sys, a Macrovision driver shipping on Windows XP and Windows Server 2003, disclosed via Security Advisory 944653 on November 5, 2007.
The pattern matters because each incident widens the trust boundary: an attacker no longer needs a bug in Windows itself when a licensed third-party driver holds the same kernel privileges. Microsoft's choice to publish an interim advisory while working jointly with Macrovision — rather than waiting for the next Patch Tuesday — echoes the emergency posture it adopted during the WMF episode.
First-order effects
- Windows XP and Windows Server 2003 machines carrying the Macrovision driver face a confirmed privilege-elevation path to complete system takeover until a fix ships.
- Microsoft and Macrovision are now on the hook jointly: Microsoft fields the advisory and mitigation guidance, while Macrovision owns remediation of its own driver.
Second-order effects
- Enterprises running XP and Server 2003 fleets must weigh disabling or removing the affected driver against breaking any applications that depend on it — a trade-off unique to bundled third-party code.
- Other ISVs whose drivers ship inside Windows face heightened scrutiny from customers and Microsoft alike, since the advisory sets a precedent that a vendor's kernel code can trigger platform-level disclosure.
Third-order effects
- If third-party kernel drivers keep producing takeover-class flaws, expect Microsoft to tighten how outside code earns privileged placement in Windows and to favor faster interim advisories over silent patch-cycle waits.
- The recurring zero-day cadence — WMF in 2005, QuickTime in January 2007, Macrovision now — pushes security budgets toward defense-in-depth assumptions that any installed component, not just the OS vendor's, is exploitable.
The trend: Third-party software embedded in Windows is emerging as a recurring privileged attack surface, forcing Microsoft into a joint-advisory workflow with component vendors between scheduled patch cycles.